Electromagnetic type automatic balancing actuator

Abstract

The invention discloses an electromagnetic type automatic balance actuator which is mainly composed of a movable ring and a static ring, the movable ring synchronously rotates along with a rotor, an outer excitation ring on a shell of the movable ring and a coaxial inner excitation ring synchronously rotate along with the rotor by means of self-locking of a permanent magnet on a balance weight disc, and the inner excitation ring is connected with the balance weight disc through a supporting bearing. A copper coil wound on a coil framework is electrified to excite a magnetic field, and magnetized soft iron realizes stepping motion of a counterweight disc to drive a counterweight block to rotate, so that mass distribution in a moving ring is changed, and unbalanced vibration of a rotor is inhibited on line; the static ring is used for generating an alternating magnetic field to drive the counterweight disc to act. According to the electromagnetic type automatic balancing actuator, the layout of a magnetic circuit and parts is optimized, and the problems that the area arrangement of excitation components of an original structure is unreasonable, and the magnetic leakage phenomenon of the magnetic circuit is serious are solved through the optimization of the magnetic circuit; the problems of rub-impact and low operation stability are solved through part layout optimization, the working efficiency of the actuator is greatly improved, and the service life of the actuator is greatly prolonged.

Description

Technical Field

[0001] The invention relates to a device for suppressing unbalanced vibration, in particular to an electromagnetic automatic balancing actuator. Background Art

[0002] The automatic balancing actuator has been considered the best solution to solve the problem of unbalanced vibration because it can automatically suppress the unbalance fault of the rotating machinery rotor online, has a fast balancing speed, and does not require the equipment to stop during the balancing process. At present, online automatic balancing systems are standard on high-end grinding machines abroad, and the vibration suppression effect is significant. Among them, the automatic balancing actuator is an actuator that forms the compensation vector, and its working effect directly determines the effect of vibration suppression.

[0003] Beijing University of Chemical Technology invented the integrated side-excitation electromagnetic slip ring automatic balancing actuator (ZL201610811273.3) in 2016. The focus of the invention is to design an electromagnetic slip ring automatic balancing actuator suitable for shaft end and shaft internal installation, which expands the application field of this type of balancing actuator. The dynamic and static rings inside the balancing actuator are both integrated structures. There is no need to adjust the gap between the dynamic and static rings during on-site installation, which greatly reduces the installation difficulty of this type of product. Breakthroughs have been achieved in both installation methods and integrated structures.

[0004] Due to the limitation of the traditional "axial excitation" method, that is, the excitation ring used to transmit the magnetic field is symmetrically distributed along the axial direction, the above-mentioned automatic balancing actuator has the disadvantages of small balancing ability, low working stability, and excessive driving voltage. In 2019, Beijing University of Chemical Technology invented the electromagnetic automatic balancing actuator (ZL201911050276.X), and the excitation method was changed from "axial excitation" to "radial excitation". The inner excitation ring teeth, the permanent magnet of the counterweight disk, and the outer excitation ring teeth are arranged radially in the actuator. The magnetic flux lines generated at this location in the structure after excitation are arranged radially, and only radial electromagnetic force is generated between the excitation ring and the counterweight disk. The radial excitation structure greatly reduces the air gap between the excitation structures, improves the self-locking / driving torque, increases stability, and improves driving efficiency, providing a basis for this drive technology.

[0005] like Figure 3aAs shown, it is a radially excited electromagnetic automatic balancing actuator. It can be seen that in the original actuator, the central stator 10' is a static ring, and the inner excitation ring 3' is a dynamic ring. The two complete the transition between the dynamic and static rings through the bearing 27'. By analyzing the assembly process of the original actuator, it can be seen that the actuator structure has at least the following two problems: (1) The position of the rotating bearing is not set reasonably: the rotating bearings 27' on both sides need to be interference fit with the central stator 10' and the inner excitation ring 3' on both sides. After the rotating bearing on one side is installed, it is difficult to install and accurately position the rotating bearing on the other side; and because the rotating bearings 27' on both sides share a central stator 10', it is extremely difficult to remove the central stator 10' and the rotating bearing 27' when the actuator needs to disassemble them; (2) There is no positioning at the outer diameter of the excitation skeleton 8': the inner diameter of the excitation skeleton 8' is axially positioned with the central stator 10', but the outer diameter of the excitation skeleton 8' is not positioned with any parts; this structure will cause the magnetic circuit to be transmitted from the outer diameter of the excitation skeleton 8' to the outer excitation ring 20'. Due to the influence of magnetic attraction, the outer diameter of the excitation skeleton 8' of the static ring is attracted toward the outer excitation ring 20' of the dynamic ring, and even friction and other faults may occur. Figure 3b As shown by the arrows, the high-speed rotating dynamic ring component collides with the stationary static ring component, which will cause the static ring to be subjected to an instantaneous radial force in the same direction of rotation, causing the static ring to rotate, seriously affecting the safety and operational reliability of the actuator.

[0006] Therefore, it is necessary to improve the original actuator structure to solve the existing friction hazards, so that it can operate reliably and safely, have a longer service life and higher work efficiency. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an electromagnetic automatic balancing actuator which has reliable and safe operation, longer service life and higher working efficiency.

[0008] In order to solve one of the above technical problems, the present invention adopts the following technical solution:

[0009] The electromagnetic automatic balancing actuator of the present invention comprises a moving ring, a static ring, a controller, and a driving power supply. The moving ring comprises a moving ring housing and a pair of external excitation rings, a counterweight plate, a pair of internal excitation rings, an internal counterweight block, an external counterweight block, a bearing connector, a support bearing, and a pair of large locking nuts located in the moving ring housing. The entire moving ring parts are symmetrically distributed along the center of the moving ring housing. The moving ring housing is fixed to the end of the rotor shaft. The inner wall of the moving ring housing is stepped and a skeleton with a T-shaped cross section is formed in the middle of the inner wall. The thickness of the inner wall of the moving ring housing gradually decreases from the middle T-shaped skeleton to both ends. The internal excitation ring is sleeved on the middle of the central stator. The outer surface, the outer wall of the inner excitation ring is fixed to the T-shaped frame, a pair of the outer excitation rings are symmetrically fixed on both sides of the T-shaped frame and are respectively located outside a pair of inner excitation rings; the inner counterweight block, the outer counterweight block and a pair of support bearings are installed on both sides of the counterweight plate; the support bearing is installed between the counterweight plate and the inner excitation ring, the inner ring of the support bearing is fixed to the inner excitation ring, and the outer ring of the support bearing is fixed to the counterweight plate; two large locking nuts are respectively installed on the outside of the two support bearings and locked with the inner excitation ring; the counterweight plate is equipped with multiple groups of permanent magnet groups and multiple groups of soft iron groups spaced apart from the permanent magnet groups, the permanent magnets The group and the soft iron group are both located between the inner excitation ring and the outer excitation ring, each group of permanent magnet groups includes a pair of permanent magnets with opposite magnetic poles, and each group of soft iron groups includes multiple soft irons arranged at intervals, and the copper coil can cooperate with the permanent magnet group and the soft iron group to drive the counterweight plate to rotate and then drive the inner counterweight block and the outer counterweight block to rotate; the static ring is located in the outer shell of the dynamic ring, and the static ring includes a pair of excitation skeletons, a pair of rotating bearings, a coil skeleton, and the central stator; the central stator adopts a hollow stepped shaft, and the central stator is fixed at the axial center hole of the excitation skeleton; the excitation skeleton is coaxially arranged with the inner excitation ring and the outer excitation ring and is located in the outer shell of the dynamic ring. Both sides of the outer excitation ring and the inner excitation ring; the two excitation skeletons are fixed on the outer surface of the central stator and positioned by the stepped shaft on the outer surface of the central stator, the two excitation skeletons are located in the moving ring, the outer wall of the excitation skeleton is stepped, the rotating bearing is installed at the step of the outer wall of the excitation skeleton, the inner ring of the rotating bearing is fixed to the excitation skeleton, and the outer ring of the rotating bearing is fixedly connected to the inner wall of the moving ring housing through a bearing connector; the two coil skeletons are fixed on the opposite inner sides of the two excitation skeletons, each of the coil skeletons is wound with a copper coil, the copper coil is electrically connected to the driving power supply through the controller, and the driving power supply supplies power to the coil.

[0010] The electromagnetic automatic balancing actuator of the present invention comprises an even number of outer excitation ring rectangular teeth evenly distributed on the circumference of the inner wall of the outer excitation ring, an even number of inner excitation ring rectangular teeth evenly distributed on the circumference of the outer wall of the inner excitation ring, the number of the outer excitation ring rectangular teeth is equal to the number of the inner excitation ring rectangular teeth and the positions correspond one to one, each permanent magnet group corresponds to an outer excitation ring rectangular tooth and an inner excitation ring rectangular tooth, a pair of permanent magnets in each permanent magnet group are symmetrically distributed, the magnetic poles of two adjacent permanent magnets are opposite, and each soft iron corresponds to an outer excitation ring rectangular tooth and an inner excitation ring rectangular tooth.

[0011] The electromagnetic automatic balancing actuator of the present invention comprises 12 permanent magnets and 20 soft irons, the N poles of the permanent magnets face the rectangular teeth of the outer excitation ring, and the S poles of the permanent magnets face the rectangular teeth of the inner excitation ring. The structures of the rectangular teeth of the outer excitation ring and the rectangular teeth of the inner excitation ring are the same and the number of the teeth is 18.

[0012] The electromagnetic automatic balancing actuator of the present invention, wherein the static ring also includes a pair of small locking nuts respectively installed on the outer sides of the two excitation skeletons and locked and fixed with the central stator, a positioning groove is opened at the center of the excitation skeleton, and a raised step is arranged on the central stator at a position corresponding to the positioning groove, and the positioning groove and the raised step cooperate to complete the positioning of the excitation skeleton and the central stator and fix them through the small locking nuts.

[0013] The electromagnetic automatic balancing actuator of the present invention, wherein the inner counterweight block and the outer counterweight block are semicircular, and are respectively mounted on the opposite inner and outer sides of two counterweight plates.

[0014] The electromagnetic automatic balancing actuator of the present invention, wherein the coil frame is fixed on the excitation frame by screws.

[0015] The electromagnetic automatic balancing actuator of the present invention comprises the following: the central stator, the excitation frame, the outer excitation ring and the inner excitation ring are made of soft magnetic materials; the movable ring housing and the counterweight plate are made of magnetic isolation materials; and the inner counterweight block and the outer counterweight block are made of stainless steel or other metal materials.

[0016] The electromagnetic automatic balancing actuator of the present invention has a reference magnet installed at one of the rotating bearings, and a reference Hall element installed at the corresponding position of the excitation skeleton. The reference Hall element senses the position of the reference magnet and is connected to the controller through a wire.

[0017] The electromagnetic automatic balancing actuator of the present invention comprises a counterweight plate Hall element installed on each coil frame facing the counterweight plate, a Hall magnet is installed on the counterweight plate at the corresponding position of the two counterweight plate Hall elements, the S pole of the Hall magnet is opposite to the front of the counterweight plate Hall element, the counterweight plate Hall element senses the position of the Hall magnet, and is connected to the controller through a wire.

[0018] The electromagnetic automatic balancing actuator of the present invention, wherein the movable ring housing is cylindrical with two ends open, and a ring-shaped protrusion is formed on the outer surface of the end of the movable ring housing for connecting with the flange and fixing the movable ring housing to the end of the rotor shaft through the flange.

[0019] Compared with the background technology, the electromagnetic automatic balancing actuator of the present invention has the following beneficial effects:

[0020] After further structural analysis, magnetic circuit analysis and simulation analysis of the original actuator, the problems mentioned in the background technology were integrated, and it was confirmed that the original actuator structure had three main problems: (1) The layout of the actuator parts is unreasonable and the operating reliability is poor. During the operation of the outer diameter of the excitation skeleton, the magnetic attraction will cause friction with the actuator moving ring, causing great safety hazards during application or experiment. (2) The area setting of the excitation component is unreasonable, and the magnetic induction intensity is unevenly distributed. The magnetic induction intensity at the center stator and the inner diameter of the excitation skeleton is too saturated, resulting in obstruction of subsequent magnetic circuit transmission, causing extremely uneven distribution of magnetic induction intensity. (3) The magnetic circuit has serious magnetic leakage and low magnetic field transmission efficiency. The magnetic circuit is "square" in shape and has many "90°" mutations in direction, resulting in extremely serious magnetic leakage. The magnetic potential fails to effectively act on the key excitation components, seriously affecting the magnetic field transmission efficiency.

[0021] The electromagnetic automatic balancing actuator of the present invention aims at the first problem of the actuator, namely, the problem of unreasonable parts design, and redesigns the structure of the related parts of the actuator. The superficial reason for the friction between the dynamic and static rings is that the electromagnetic attraction causes the axial displacement at the outer diameter of the excitation skeleton, which rubs against the dynamic ring; the fundamental reason is that there is no displacement restriction at the outer diameter of the excitation skeleton. The entire interior of the actuator is affected by the electromagnetic force, but only the outer diameter of the excitation skeleton is displaced, indicating that it is necessary to optimize and improve the structure at the outer diameter of the excitation skeleton so that it will not undergo axial displacement during the operation of the actuator, thereby ensuring the stable operation of the actuator. The present invention connects the excitation skeleton to the outer shell of the dynamic ring by means of a rotating bearing, so that the excitation skeleton is positioned at both the inner and outer diameters, limiting its radial and axial displacement, solving the problem of friction with the dynamic ring, and ensuring reliable and safe operation and a longer service life.

[0022] The electromagnetic automatic balancing actuator described in the present invention optimizes the magnetic conductive area of ​​each excitation component to address the second actuator problem, namely, the unreasonable distribution of magnetic induction intensity. The reason for the unreasonable distribution of magnetic induction intensity is the unreasonable distribution of the magnetic circuit area. When the magnetic field is transmitted, the magnetic conductive area at a certain excitation component is too small, resulting in the concentration of magnetic induction intensity. This phenomenon will affect the smooth transmission of the magnetic circuit, resulting in the unreasonable distribution of magnetic induction intensity at other excitation components. By partitioning the magnetic conductive areas of all excitation components on the magnetic circuit, combining the magnetic circuit transmission principle, and redistributing the magnetic circuit area, the phenomenon of magnetic induction intensity concentration is avoided, which helps the smooth transmission of the subsequent magnetic circuit and improves work efficiency.

[0023] The electromagnetic automatic balancing actuator described in the present invention optimizes the structural mutations of each excitation component to address the third problem of the actuator, namely, the serious magnetic circuit leakage phenomenon. The reasons for the serious magnetic circuit leakage phenomenon are that there are many places in the magnetic circuit with large magnetic potential and short paths, and secondly, there are many directional mutations in the magnetic circuit. By increasing the magnetic circuit area at the structural mutation points and setting appropriate chamfers, while adjusting the overall magnetic circuit shape to become a smooth circular magnetic circuit, the magnetic field transfer efficiency is improved, that is, the work efficiency is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the overall assembly structure design diagram of the electromagnetic automatic balancing actuator of the present invention;

[0025] Figure 2a , 2b It is a diagram showing the arrangement of the magnets on the counterweight plate and the installation position of the Hall element in the electromagnetic automatic balancing actuator of the present invention;

[0026] Figure 3a , 3b This is a structural analysis diagram of the original structure of the electromagnetic automatic balancing actuator;

[0027] Figure 4a It is a schematic diagram of the existing structure of an electromagnetic automatic balancing actuator;

[0028] Figure 4b It is a structural improvement diagram of the electromagnetic automatic balancing actuator of the present invention;

[0029] Figure 5a It is a magnetic circuit area diagram of the existing structure of the electromagnetic automatic balancing actuator;

[0030] Figure 5b It is a magnetic circuit area optimization diagram of the electromagnetic automatic balancing actuator of the present invention;

[0031] Figure 6a It is a magnetic circuit shape diagram of the existing structure of the electromagnetic automatic balancing actuator;

[0032] Figure 6bIt is a magnetic circuit shape optimization diagram of the electromagnetic automatic balancing actuator of the present invention;

[0033] Figure 7 It is a schematic diagram of the connection between the electromagnetic automatic balancing actuator, the controller and the rotor of the present invention;

[0034] in:

[0035] 1-Hall magnet, 2-balance plate Hall element, 3-reference magnet, 4-reference Hall element, 5-dynamic ring housing, 6-excitation frame, 7-external excitation ring, 8-balance plate, 9-internal excitation ring, 10-internal counterweight, 11-external counterweight, 12-bearing connector, 13-

[0036] Rotating bearing, 14-coil skeleton, 15-support bearing, 16-large locking nut, 17-center stator, 18-small locking nut, 19-controller, 20-driving power supply, 21-rotor, 22-flange, 51-annular connecting protrusion, 71-external excitation ring rectangular teeth, 81-permanent magnet group, 82-soft iron group, 91-internal excitation ring rectangular teeth. DETAILED DESCRIPTION

[0037] like Figure 1 , 7 As shown, the electromagnetic automatic balancing actuator of the present invention includes a moving ring, a stationary ring, a controller 19, and a driving power supply 20. The moving ring is the part that rotates with the main shaft of the rotating mechanical rotor, and the stationary ring is the part that remains stationary and does not rotate. A rotating bearing 13 is installed between the moving ring and the stationary ring to ensure the relative rotation between the two. The actuator has a symmetrical structure as a whole, that is, the parts on the left and right sides are exactly the same and symmetrically distributed.

[0038] like Figure 1As shown, the moving ring includes two Hall magnets 1, a reference magnet 3, a moving ring housing 5 and a pair of external excitation rings 7, a counterweight plate 8, a pair of internal excitation rings 9, an internal counterweight block 10, an external counterweight block 11, a bearing connector 12, a support bearing 15 and a pair of large locking nuts 16 located in the moving ring housing 5; the entire moving ring parts are symmetrically distributed along the center of the moving ring housing 5; wherein the moving ring housing 5 is fixed to the end of the rotating shaft of the rotor 1', the moving ring housing 5 is a cylindrical shape with openings at both ends, the inner wall of the moving ring housing 5 is stepped and a skeleton 52 with a T-shaped cross section is formed in the middle of the inner wall, and the thickness of the inner wall of the moving ring housing 5 gradually decreases from the middle T-shaped skeleton 52 to both ends; the internal excitation ring 9 is sleeved in the middle of the central stator 17 The outer surface of the part, the outer wall of the inner excitation ring 9 is fixed to the T-shaped frame 52 by a threaded connection, and a pair of external excitation rings 7 are symmetrically fixed on both sides of the T-shaped frame 52 and are respectively located outside a pair of inner excitation rings; an inner counterweight block 10, an outer counterweight block 11 and a pair of support bearings 15 are installed on both sides of the counterweight plate 8; the inner counterweight block 10 and the outer counterweight block 11 are semicircular, and they are respectively installed on the opposite inner and outer sides of the two counterweight plates 8; the support bearing 15 is installed between the counterweight plate 8 and the inner excitation ring 9, the inner ring of the support bearing 15 is fixed to the inner excitation ring 9, and the outer ring of the support bearing 15 is fixed to the counterweight plate 8; two large locking nuts 16 are respectively installed on the outer sides of the two support bearings 15 and are locked and fixed with the inner excitation ring 9.

[0039] like Figure 2a As shown, the counterweight disc 8 is equipped with multiple groups of permanent magnet groups 81 and multiple groups of soft iron groups 82 spaced apart from the permanent magnet groups 81. The permanent magnet groups 81 and the soft iron groups 82 are both located between the inner excitation ring 9 and the outer excitation ring 7. Each group of permanent magnet groups 81 includes a pair of permanent magnets with opposite magnetic poles, and each group of soft iron groups 82 includes multiple pieces of soft iron spaced apart. The copper coil can cooperate with the permanent magnet groups 81 and the soft iron groups 82 to drive the counterweight disc 8 to rotate and thereby drive the inner counterweight block 10 and the outer counterweight block 11 to rotate.

[0040] like Figure 1As shown, the stationary ring is located in the moving ring housing 5, and the stationary ring includes two counterweight plate Hall elements 1, a reference Hall element 4, a pair of excitation skeletons 6, a pair of rotating bearings 13, a coil skeleton 14, a central stator 17, and a pair of small locking nuts 18; the central stator 17 adopts a hollow stepped shaft, and the central stator 17 is fixed at the axial center hole of the excitation skeleton 6; the excitation skeleton 6 is coaxially arranged with the inner excitation ring 9 and the outer excitation ring 7 and is located on both sides of the inner and outer excitation rings 7 and the inner excitation ring 9 of the moving ring housing 5; the two excitation skeletons 6 are fixed on the outer surface of the central stator 17 and pass through the center The stepped shaft positioning on the outer surface of the stator 17, the two excitation skeletons 6 are located on the outer wall of the dynamic ring excitation skeleton 6 in a stepped shape, the rotating bearing 13 is installed at the step of the outer wall of the excitation skeleton 6, the inner ring of the rotating bearing 13 is fixed to the excitation skeleton 6, and the outer ring of the rotating bearing 13 is fixedly connected to the inner wall of the dynamic ring housing 5 through the bearing connector 12; the two coil skeletons 14 are fixed to the opposite inner sides of the two excitation skeletons 6 by screws, and a copper coil is wound inside each coil skeleton 14, and the copper coil is electrically connected to the driving power supply 20 through the controller 19, and the driving power supply 20 supplies power to the coil.

[0041] Furthermore, if Figure 2a As shown, an even number of outer excitation ring rectangular teeth 71 are evenly distributed on the circumference of the inner wall of the outer excitation ring 7, and an even number of inner excitation ring rectangular teeth 91 are evenly distributed on the circumference of the outer wall of the inner excitation ring 9. The number of the outer excitation ring rectangular teeth 71 is equal to the number of the inner excitation ring rectangular teeth 91 and their positions correspond one to one. Each permanent magnet group 81 corresponds to an outer excitation ring rectangular tooth 71 and an inner excitation ring rectangular tooth 91. A pair of permanent magnets in each permanent magnet group 81 are symmetrically distributed, and the magnetic poles of two adjacent permanent magnets are opposite. Each soft iron corresponds to an outer excitation ring rectangular tooth 71 and an inner excitation ring rectangular tooth 91.

[0042] like Figure 2a As shown, there are 12 permanent magnets and 20 soft irons. The N poles of the permanent magnets face the outer excitation ring rectangular teeth 71, and the S poles of the permanent magnets face the inner excitation ring rectangular teeth 91. The outer excitation ring rectangular teeth 71 and the inner excitation ring rectangular teeth 91 have the same structure and both have 18 teeth.

[0043] like Figure 1 As shown, the static ring also includes a pair of small locking nuts 18 which are respectively installed on the outer sides of the two excitation skeletons 6 and locked and fixed with the central stator 17. A positioning groove is opened at the center of the excitation skeleton 6, and a raised step is provided on the central stator 17 at a position corresponding to the positioning groove. The positioning groove and the raised step cooperate to complete the positioning of the excitation skeleton 6 and the central stator 17 and fix them through the small locking nuts 18.

[0044] In the electromagnetic automatic balancing actuator of the present invention, the central stator 17, the excitation frame 6, the outer excitation ring 7, and the inner excitation ring 9 are made of soft magnetic materials; the moving ring housing 5 and the counterweight plate 8 are made of magnetic isolation materials, and the inner counterweight block 10 and the outer counterweight block 11 are made of stainless steel or other metal materials.

[0045] In the electromagnetic automatic balancing execution of the present invention, the gap δ1 between the outer wall of the central stator 17 and the inner wall of the inner excitation ring 9 is 0.6 mm, the gap δ2 between the relatively positioned outer excitation ring rectangular teeth, the inner excitation ring rectangular teeth and the permanent magnet is 0.5 mm, and the gap δ1 between the outer excitation ring 7 and the coil skeleton 14 is 0.6 mm.

[0046] like Figure 1 As shown, a reference magnet 3 is installed at one of the rotating bearings, and a reference Hall element 4 is installed at the corresponding position of the excitation frame 6. The reference Hall element 4 senses the position of the reference magnet 3 and is connected to the controller 19 through a wire; Figure 1 , Figure 2a , Figure 2b As shown, each coil frame 14 facing the counterweight plate 8 is equipped with a counterweight plate Hall element 2, and a Hall magnet 1 is installed at the corresponding position of the two counterweight plate Hall elements 2 on the counterweight plate 8, and the S pole of the Hall magnet 1 is opposite to the front of the counterweight plate Hall element 2. The counterweight plate Hall element 2 senses the position of the Hall magnet 1 and is connected to the controller 19 through a wire.

[0047] like Figure 7 As shown, the moving ring housing 5 is cylindrical with two ends opened. An annular protrusion 51 is formed on the outer surface of the end of the moving ring housing 5 for connecting with the flange and fixing the moving ring housing 5 to the end of the rotating shaft of the rotor 1' through the flange 2'.

[0048] In the absence of an external magnetic field, the magnetic field formed between the permanent magnet and the inner excitation ring 9 and the outer excitation ring 7 is relied on to make the permanent magnet and the inner excitation ring 9 and the outer excitation ring 7 have a self-locking force of mutual attraction, so as to ensure that when the rotor rotates at a constant speed and accelerates and decelerates, the counterweight plate 8 rotates synchronously with the rotor and can not rotate relative to the rotor within a certain acceleration and deceleration. The magnetic path of the permanent magnet is: it is emitted from the N pole of a permanent magnet, passes through the rectangular tooth 71 of the outer excitation ring, the permanent magnet adjacent to the permanent magnet, and the rectangular tooth 91 of the inner excitation ring, and finally returns to the S pole of the permanent magnet to form a closed loop. Referring to the principle of magnetic force drive technology, since the magnetic resistance of the permanent magnet magnetic field circuit is the smallest at this position, the micro-movement of the counterweight plate 8 in any direction will generate a magnetic force on the counterweight plate 8 to restore it to a stable equilibrium position, thereby preventing the counterweight plate 8 from slipping. The permanent magnet generates a force that locks the inner excitation ring 9 and the outer excitation ring 7 by passing through the magnetic lines of force of the inner excitation ring 9 and the outer excitation ring 7, i.e., a self-locking force. Due to the action of this force, the counterweight plate 8 rotates with the rotor and can not rotate relative to the rotor within a certain acceleration and deceleration, thus realizing the self-locking function of the counterweight plate 8.

[0049] The direction of the magnetic circuit is determined by the direction of the driving voltage. When the direction of the current in the coil changes, the direction of the magnetic circuit will also change. Under the action of the external magnetic field, take the counterclockwise magnetic circuit as an example for analysis. When the coil is energized, a magnetic field is excited around it, and the excitation skeleton 6 is immediately magnetized. The magnetic flux lines pass through the axial air gap δ1 between the excitation skeleton 6 and the inner excitation ring 9, and axially reach the outer excitation ring 7. Due to the structure of the outer excitation ring 7, the magnetic flux lines radially pass through the air gap δ2 between the permanent magnet and the outer excitation ring 7 and the permanent magnet on the counterweight plate 8. At this time, the tooth surface of the outer excitation ring 7 is magnetized to the N pole, and then continues to pass through the air gap δ2 between the permanent magnet and the inner excitation ring 9 to reach the inner excitation ring 9. At this time, the tooth surface of the inner excitation ring 9 is magnetized to the S pole. Because permanent magnets "repel each other with like poles and attract each other with unlike poles", and there is a pair of permanent magnets with opposite poles on the counterweight plate 8 facing the teeth of the inner excitation ring 9 and the outer excitation ring 7, the N pole of the rectangular tooth surface of the outer excitation ring 7 repels the N pole of one of the permanent magnets on the counterweight plate 8, and attracts the S pole of the other permanent magnet on the counterweight plate 8 at that position. When the repulsive force and the attractive force are at a certain angle, the counterweight plate 8 tends to rotate in steps; at this time, for the counterweight plate 8 and the inner excitation ring 9, the S pole of one of the permanent magnets on the counterweight plate 8 repels the S pole of the tooth surface of the inner excitation ring 9, and the N pole of the other permanent magnet on the counterweight plate 8 at this position attracts the S pole of the rectangular tooth surface of the inner excitation ring 9. When the repulsive force and the attractive force are at a certain angle, the counterweight plate 8 has a tendency to move, and this tendency is the same as the tendency generated between the permanent magnet on the counterweight plate 8 and the outer excitation ring 7. The two groups of movement trends are the same and superimposed on each other, driving the counterweight plate 8 to step. Then, the magnetic flux lines reach the central stator 17 along the radial structure of the inner excitation ring 9, and then along the axial side of the inner excitation ring 9 close to the central stator 17, through the axial air gap δ1 between the excitation skeleton 6 and the excitation ring and return to the excitation skeleton 6. At this point, the magnetic field excited by the energized coil passes through the excitation skeleton 6, the air gap δ1, the outer excitation ring 7, the air gap δ2, the permanent magnet on the counterweight plate 8, the inner excitation ring 9 and the central stator 17 to form a closed magnetic flux line, see Figure 6b When a clockwise magnetic circuit is required and the counterweight plate 8 is required to produce continuous clockwise motion, it is only necessary to adjust the positive and negative alternating sequence of the driving voltage. The working principle is the same as that of the counterclockwise motion and will not be described here.

[0050] Based on the above radial excitation automatic balancing actuator, the present invention improves the layout of actuator parts and optimizes the shape and area of ​​the magnetic circuit to form an actuator with higher working efficiency and longer service life.

[0051] The electromagnetic automatic balancing actuator of the present invention is mainly composed of two parts, a moving ring and a static ring. The moving ring rotates synchronously with the rotor. For example, if the flange connection end of the moving ring housing of the present invention is installed on the grinding wheel spindle, the moving ring rotates synchronously with the grinding wheel spindle. The outer excitation ring 7 on the moving ring housing 5 and the coaxial inner excitation ring 9 rotate synchronously with the rotor by relying on the permanent magnet on the counterweight plate 8 to self-lock. The inner excitation ring 9 is connected to the counterweight plate 8 through a supporting bearing 15. By energizing the copper coil wound around the coil frame 14 to excite the magnetic field, the magnetized soft iron realizes the stepping motion of the counterweight plate driven by the permanent magnet-electromagnetic combination to drive the counterweight plate. The rotation of the weight block changes the mass distribution inside the moving ring, thereby suppressing the unbalanced vibration of the rotor online; the static ring is fixed to the grinding wheel cover through a flexible connection to generate an alternating magnetic field and drive the counterweight plate to move; the static ring cooperates with the moving ring housing 5 through a rotating bearing 13, and is fixed to the central stator 17 with a small locking nut 18. After the copper coil is energized, the axial excitation is changed to radial excitation through the coil skeleton 14, the excitation skeleton 6, the outer excitation ring 7 on the moving ring, the permanent magnet and the inner excitation ring 9, thereby avoiding axial friction between the outer excitation ring 7 and the counterweight plate 8.

[0052] like Figure 1 As shown, in the electromagnetic automatic balancing actuator of the present invention, the outer excitation ring 7 and the inner excitation ring 9 are fixed to the moving ring housing 5 by screws. An inner counterweight block 10, an outer counterweight block 11 and a pair of support bearings 15 are installed on the counterweight plate 8. The counterweight block is semicircular and is used to generate a compensation vector; the support bearing 15 is installed between the counterweight plate 8 and the inner excitation ring 9 to ensure the relative rotation between the counterweight plate and the inner excitation ring when the compensation vector is formed. The large locking nut 16 is installed on the outside of the support bearing 15 to ensure the positioning between the counterweight plate 8 and the inner excitation ring 9. The moving ring assembly process mainly includes the outer excitation ring 7 and the moving ring housing 5 being connected by threads, 8 permanent magnets and 20 soft irons being installed on each counterweight plate 8, the support bearings on the counterweight plate 8 being positioned by the inner and outer counterweight blocks on both sides of the counterweight plate, and the two inner excitation rings 9 being connected by threads.

[0053] like Figure 1As shown, in the electromagnetic automatic balancing actuator of the present invention, a copper coil is wound inside the coil frame 14, which can form a magnetic field after being excited and then conduct the magnetic circuit in the actuator to start working. The coil frame 14 is fixed to the excitation frame 6 by screws. A positioning groove is opened at the center of the excitation frame 6. A raised step is provided at the corresponding position of the central stator 17 to complete the positioning with the excitation frame 6. The excitation frames 6 on both sides are positioned with the central stator 17 through the positioning groove and fixed by two small locking nuts 18. The static ring assembly process includes the installation of Hall elements on the coil frame 14 and the excitation frame 6, the installation of permanent magnets on the bearing fixing ring, the installation of the coil and the coil frame 14 into the excitation frame, and the tight fit between the static ring and the dynamic ring housing through the bearing fixing ring and the use of threaded connection. Considering the factors that the Hall element has three wires and needs power supply, three Hall elements (referring to a reference Hall element 4 and two counterweight plate Hall elements 2) are installed on the static and non-rotating static ring. The reference Hall element 4 is mounted on the excitation skeleton 6 facing the moving ring bearing, and the counterweight plate Hall element 2 is mounted on the coil skeleton 14 facing the counterweight plate 8. The Hall magnet 1 is mounted at the corresponding position of the moving ring bearing, i.e., the rotating bearing 13, on the moving ring of the actuator and the counterweight plate 8, so that the S pole of the Hall magnet 1 faces the front of the counterweight plate Hall element 2.

[0054] like Figure 3a , 3b As shown, in the original actuator, the center stator 10' is a static ring, and the inner excitation ring 3' is a dynamic ring; the two complete the transition between the static and dynamic rings through the bearing 27'. By analyzing the assembly process of the original actuator, it can be seen that there are two problems with the actuator structure: (1) The position setting of the rotating bearing 27' is unreasonable. The rotating bearings 27' on both sides need to be interference fit with the center stator 10' and the inner excitation ring 3' on both sides. After the rotating bearing on one side is installed, it is difficult to install and accurately position the rotating bearing on the other side. And because the rotating bearings on both sides share a central stator, it is extremely difficult to remove the central stator and the rotating bearing when the actuator needs to disassemble. (2) There is no positioning at the outer diameter of the excitation skeleton 8'. The inner diameter of the excitation skeleton 8' is axially positioned with the center stator 10', but the outer diameter of the excitation skeleton 8' is not positioned with any parts. This structure will cause the outer diameter of the excitation skeleton 8' of the static ring to attract the outer excitation ring 20' of the dynamic ring due to the magnetic attraction when the magnetic circuit is transmitted from the outer diameter of the excitation skeleton 8' to the outer excitation ring 20' of the dynamic ring, and even cause faults such as friction. The high-speed rotating dynamic ring parts collide with the stationary static ring parts, causing the static ring to be subjected to an instantaneous radial force in the same direction of rotation, causing the static ring to rotate, seriously affecting the safety and operational reliability of the actuator.

[0055] The structure of the inner excitation ring 9 and the moving ring housing 5 of the present invention has innovated the positioning and installation of the inner excitation ring 9, eliminated the bearing between the inner excitation ring 9 and the central stator 17, and bolted a pair of inner excitation rings 9 to the moving ring housing 5; the positioning of the inner excitation ring 9 is changed to positioning on the moving ring housing through the T-shaped frame 52 formed on the inner wall of the moving ring housing 5. After the inner excitation ring 9 and the counterweight plate 8 are assembled, a pair of inner excitation rings 9 and the counterweight plate 8 are connected to the moving ring housing 5 from both sides of the moving ring housing 5 through the threaded holes on the T-shaped frame 52, so that the inner excitation ring 9 and the outer excitation ring 7 are directly fixed to the moving ring housing 5. This makes the present invention more convenient to disassemble than the original design, and reduces the collision and friction of the moving and static rings during rotation.

[0056] Figure 4a The original excitation skeleton 8' assembly structure shown in the figure has its inner diameter matched and fixed with the central stator 10' through concave and convex grooves, and a rotating bearing 27' is installed between the central stator and the moving ring to ensure the relative rotation between the moving and static rings. There is a 0.5mm gap between its outer diameter and the moving ring shell 30' to avoid friction between the two. Figure 4b The electromagnetic automatic balancing actuator of the present invention shown in the figure cancels the 0.5mm gap set here to avoid friction, and connects the excitation skeleton 6 to the moving ring housing 5 by installing a rotating bearing 13. The auxiliary connecting piece 12 is installed on the outer diameter of the rotating bearing 13 and fixed to the moving ring housing 5 by screws. The inner diameter of the rotating bearing 13 is interference-fitted with the excitation skeleton 6 and axially fixed. In this way, the excitation skeleton 6 is positioned at the inner and outer diameters, limiting its radial and axial displacement, and solving the problem of friction with the moving ring. The improved assembly structure is shown in FIG. Figure 3b As shown. The rotating bearing uses a deep groove ball bearing, which can bear a part of the axial load while bearing the radial load. This improvement measure perfectly solves the positioning problem of the excitation skeleton 6, and the magnetic circuit shape of the excitation skeleton 6 changes from square to circular, which is conducive to the smooth transmission of the magnetic circuit.

[0057] The electromagnetic automatic balancing actuator of the present invention optimizes the magnetic conductive area of ​​each excitation component. Figure 5a The reason why the original structure caused unreasonable distribution of magnetic induction intensity is unreasonable distribution of magnetic circuit area. When the magnetic field is transmitted, the magnetic conductivity area at a certain excitation component is too small, resulting in the concentration of magnetic induction intensity. This phenomenon will affect the smooth transmission of the magnetic circuit, resulting in unreasonable distribution of magnetic induction intensity at other excitation components. Figure 5bThe present invention divides the magnetic conductive area of ​​all the excitation components on the magnetic circuit into seven zones, namely, the inner diameter zone of the excitation skeleton ①, the middle diameter zone of the excitation skeleton ②, the outer diameter zone of the excitation skeleton ③, the outer excitation ring zone ④, the inner excitation ring middle diameter zone ⑤, the inner excitation ring inner diameter zone ⑥, and the central stator zone ⑦. The distribution of the magnetic conductive area of ​​each excitation component on the magnetic circuit is optimized: (1) The area of ​​the optimized magnetic conductive component is increased from 29.5%-75.1% to 50.2%-80.0%, and the inner diameter of the central stator and the excitation skeleton is used as the starting point of the entire magnetic circuit, which ensures that its magnetic conductive area is large enough and the magnetic circuit is wide enough, which is conducive to the smooth transmission of the subsequent magnetic circuit. (2) The magnetic conductive area of ​​the five zones, namely, the middle diameter zone of the excitation skeleton ②, the outer diameter zone of the excitation skeleton ③, the outer excitation ring zone ④, the inner excitation ring middle diameter zone ⑤, and the inner diameter zone ⑥ of the inner excitation ring are evenly distributed, thereby ensuring the uniform transmission of the magnetic circuit and solving the problem of unreasonable distribution of magnetic induction intensity.

[0058] In the electromagnetic automatic balancing actuator of the present invention, the structural design of the excitation components is optimized with respect to the structural mutations of each excitation component, and a quarter of the structure of the actuator is taken for magnetic circuit analysis. Figure 6a The reasons why the original structure shown causes serious magnetic leakage in the magnetic circuit are that, firstly, there are many places with large magnetic potential and short paths in the magnetic circuit, and secondly, there are many places with sudden changes in direction in the magnetic circuit. Figure 6b The excitation structure of the present invention increases the magnetic circuit area at the structural mutation and sets a suitable chamfer to make the magnetic circuit transfer transition smoother. The overall magnetic circuit shape is adjusted from the original square magnetic circuit with multiple "90°" mutations to a smooth circular magnetic circuit, making the magnetic circuit transfer smoother, reducing the occurrence of magnetic leakage, and improving the magnetic field transfer efficiency.

[0059] The embodiments described above are merely descriptions of preferred implementations of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An electromagnetic automatic balancing actuator, comprising a moving ring, a stationary ring, a controller (19), and a driving power supply (20), characterized in that: The dynamic ring comprises a dynamic ring housing (5) and a pair of external excitation rings (7), a counterweight plate (8), a pair of internal excitation rings (9), an internal counterweight block (10), an external counterweight block (11), a bearing connector (12), a support bearing (15) and a pair of large locking nuts (16) located inside the dynamic ring housing (5); the entire dynamic ring parts are symmetrically distributed along the center of the dynamic ring housing (5); The movable ring housing (5) is fixed to the end of the rotating shaft of the rotor (1'), the inner wall of the movable ring housing (5) is stepped and a frame (52) with a T-shaped cross section is formed in the middle of the inner wall, and the thickness of the inner wall of the movable ring housing (5) gradually decreases from the middle T-shaped frame (52) to both ends; The inner excitation ring (9) is sleeved on the middle outer surface of the central stator (17), the outer wall of the inner excitation ring (9) is fixed to the T-shaped frame (52), and a pair of outer excitation rings (7) are symmetrically fixed on both sides of the T-shaped frame (52) and are respectively located outside the pair of inner excitation rings; The inner counterweight block (10), the outer counterweight block (11) and a pair of support bearings (15) are installed on both sides of the counterweight plate (8); the support bearing (15) is installed between the counterweight plate (8) and the inner excitation ring (9), the inner ring of the support bearing (15) is fixed to the inner excitation ring (9), and the outer ring of the support bearing (15) is fixed to the counterweight plate (8); two large locking nuts (16) are respectively installed on the outer sides of the two support bearings (15) and are locked and fixed to the inner excitation ring (9); The counterweight disc (8) is provided with a plurality of permanent magnet groups (81) and a plurality of soft iron groups (82) spaced apart from the permanent magnet groups (81); the permanent magnet groups (81) and the soft iron groups (82) are both located between the inner excitation ring (9) and the outer excitation ring (7); each permanent magnet group (81) includes a pair of permanent magnets with opposite magnetic poles; each soft iron group (82) includes a plurality of soft irons spaced apart; the copper coil can cooperate with the permanent magnet groups (81) and the soft iron groups (82) to drive the counterweight disc (8) to rotate, thereby driving the inner counterweight block (10) and the outer counterweight block (11) to rotate; The stationary ring is located in the housing (5) of the moving ring, and the stationary ring comprises a pair of excitation skeletons (6), a pair of rotating bearings (13), a coil skeleton (14), and the central stator (17); The central stator (17) adopts a hollow stepped shaft, and the central stator (17) is fixed at the axial center hole of the excitation frame (6); The excitation frame (6) is coaxially arranged with the inner excitation ring (9) and the outer excitation ring (7) and is located on both sides of the inner and outer excitation rings (7) and the inner excitation ring (9) of the dynamic ring housing (5); The two excitation frames (6) are fixedly mounted on the outer surface of the central stator (17) and positioned by the stepped shaft on the outer surface of the central stator (17). The two excitation frames (6) are located on the outer wall of the excitation frames (6) of the moving ring and are stepped. The rotating bearing (13) is mounted on the stepped part of the outer wall of the excitation frames (6). The inner ring of the rotating bearing (13) is fixed to the excitation frames (6). The outer ring of the rotating bearing (13) is fixedly connected to the inner wall of the moving ring housing (5) by a bearing connector (12). The two coil frames (14) are fixed on opposite inner sides of the two excitation frames (6), and a copper coil is wound inside each coil frame (14). The copper coil is electrically connected to a driving power supply (20) through a controller (19), and the driving power supply (20) supplies power to the coil.

2. The electromagnetic automatic balancing actuator according to claim 1, characterized in that: An even number of outer excitation ring rectangular teeth (71) are evenly distributed on the circumference of the inner wall of the outer excitation ring (7), and an even number of inner excitation ring rectangular teeth (91) are evenly distributed on the circumference of the outer wall of the inner excitation ring (9); the number of the outer excitation ring rectangular teeth (71) is equal to the number of the inner excitation ring rectangular teeth (91), and the positions correspond one to one; each permanent magnet group (81) corresponds to an outer excitation ring rectangular tooth (71) and an inner excitation ring rectangular tooth (91); a pair of permanent magnets in each permanent magnet group (81) are symmetrically distributed, and the magnetic poles of two adjacent permanent magnets are opposite; and each soft iron corresponds to an outer excitation ring rectangular tooth (71) and an inner excitation ring rectangular tooth (91).

3. The electromagnetic automatic balancing actuator according to claim 2, characterized in that: There are 12 permanent magnets in total and 20 soft irons in total. The N poles of the permanent magnets face the outer excitation ring rectangular teeth (71), and the S poles of the permanent magnets face the inner excitation ring rectangular teeth (91). The outer excitation ring rectangular teeth (71) and the inner excitation ring rectangular teeth (91) have the same structure and both have 18 teeth.

4. The electromagnetic automatic balancing actuator according to claim 3, characterized in that: The stationary ring also includes a pair of small locking nuts (18) respectively mounted on the outer sides of the two excitation frames (6) and locked and fixed with the central stator (17); a positioning groove is provided at the center of the excitation frame (6); a raised step is provided on the central stator (17) at a position corresponding to the positioning groove; the positioning groove and the raised step cooperate to position the excitation frame (6) and the central stator (17) so as to be fixed by the small locking nuts (18).

5. The electromagnetic automatic balancing actuator according to claim 4, characterized in that: The inner counterweight block (10) and the outer counterweight block (11) are semicircular and are respectively mounted on the inner and outer sides of the two counterweight plates (8) at opposite sides.

6. The electromagnetic automatic balancing actuator according to claim 5, characterized in that: The coil frame (14) is fixed on the excitation frame (6) by means of screws.

7. The electromagnetic automatic balancing actuator according to claim 6, characterized in that: The central stator (17), the excitation frame (6), the outer excitation ring (7), and the inner excitation ring (9) are made of soft magnetic materials; the movable ring housing (5) and the counterweight plate (8) are made of magnetic isolation materials; and the inner counterweight block (10) and the outer counterweight block (11) are made of stainless steel or other metal materials.

8. The electromagnetic automatic balancing actuator according to claim 7, characterized in that: A reference magnet (3) is installed at one of the rotating bearings, and a reference Hall element (4) is installed at a corresponding position of the excitation frame (6). The reference Hall element (4) senses the position of the reference magnet (3) and is connected to a controller (19) via a wire.

9. The electromagnetic automatic balancing actuator according to claim 8, characterized in that: A counterweight plate Hall element (2) is installed on each coil frame (14) facing the counterweight plate (8), and a Hall magnet (1) is installed on the counterweight plate (8) at the corresponding position of the two counterweight plate Hall elements (2). The S pole of the Hall magnet (1) faces the front of the counterweight plate Hall element (2). The counterweight plate Hall element (2) senses the position of the Hall magnet (1) and is connected to the controller (19) through a wire.

10. The electromagnetic automatic balancing actuator according to claim 9, characterized in that: The movable ring housing (5) is cylindrical with openings at both ends. The outer surface of the end of the movable ring housing (5) is formed with a ring-shaped protrusion (51) for connecting with the flange and fixing the movable ring housing (5) to the end of the rotating shaft of the rotor (1') through the flange (2').

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