A multi-magnetic circuit moving-magnet linear oscillating motor

Abstract

The present invention discloses a multi-magnetic-circuit moving-magnet linear oscillating motor, which includes front and rear frames, left and right end plates, an inner yoke, an outer stator group, a mover, and a resonant spring; the outer stator group includes two sets of outer stators, and each outer stator includes an outer yoke, a winding on the tooth columns of the outer yoke and a fixed coil on the outer tooth columns. Two coils are wound on the middle two tooth columns of the outer yoke and magnetize the middle two tooth columns. The magnetization intensity of the outer tooth columns is relatively weaker than that of the middle two tooth columns. The magnetization intensity of the outer tooth columns is enhanced by the coils fixed on the outer tooth columns of the outer yoke to ensure that the magnetic fluxes of the tooth columns forming the magnetic circuit are equal; the magnetic flux forms a complete closed magnetic circuit through the outer stator group, the permanent magnet, the air gap, and the inner yoke; the outer stator group, the permanent magnet, and the inner yoke are all coaxially installed. The present invention improves the difference in magnetic flux of the magnetic circuit during the operation of the motor, makes the magnetic circuit stable, forms multiple closed magnetic circuits, improves the utilization rate of the permanent magnet, has stable electromagnetic force output, and has a large adjustable range of stroke.

Description

Technical Field

[0001] The present invention relates to the field of motor design, and particularly to a multi-magnetic-circuit moving-magnet linear oscillating motor. Background Art

[0002] When driving a linear motion load, a linear motor eliminates the crank-link mechanism for converting a rotary motor into a linear motion, making the overall structure simple, with fast response speed, good working performance, and low noise. It reduces the intermediate losses caused by mechanical friction and improves the motor operation efficiency. In recent years, with the increasingly wide application of linear motors, the research on linear motors has gradually become a hot spot in R & D and has been widely used in military, medical, aerospace, refrigeration, electromagnetic guns and other fields.

[0003] The moving direction of the mover of a permanent magnet linear motor is perpendicular to the closed magnetic field path formed by the motor, forming a transverse flux motor. The magnetic circuit and the circuit formed by the motor do not interfere with each other and are independent, and multiple magnetic circuits can be formed. In a moving-magnet linear motor, when the coil is energized, the magnetization intensity of the yoke is different, resulting in unbalanced magnetic flux in the magnetic circuit and unstable electromagnetic output force. Moreover, the coil is installed inside the motor, which causes the motor temperature to rise and the motor to operate unstably. Summary of the Invention

[0004] Aiming at the above technical problems, the purpose of the present invention is to provide a multi-magnetic-circuit moving-magnet linear oscillating motor, which can reduce the possibility of magnetic leakage, make the magnetic circuit complete during the movement of the mover, output stable electromagnetic force, dissipate heat from the coil in time, and reduce the temperature of the motor.

[0005] To achieve the above object, the present invention provides a multi-magnetic-circuit moving-magnet linear oscillating motor, including: front and rear frames, an outer stator group fixing device disposed at the middle position between the front and rear frames, an outer stator group installed on the outer stator group fixing device, an inner stator installed inside the outer stator group, and a mover installed between the outer stator group and the inner stator; the outer stator group, the mover and the inner yoke are coaxially installed.

[0006] The mover is composed of a magnetic frame and permanent magnets. The permanent magnets are embedded in the magnetic frame and installed between the outer stator group and the inner yoke. Further, there are two types of the specified permanent magnets. The permanent magnets adopt a radial magnetization direction, and are arranged in the circumferential direction in the order of small, large, small, small, large, small. The permanent magnets are arranged in a single N and S pole pattern, and four groups are evenly arrayed along the axial direction. The large-sized permanent magnets are installed corresponding to the two middle tooth columns of the outer yoke, and the small-sized permanent magnets are installed corresponding to the outer tooth columns of the outer yoke. Further, the shape of the permanent magnets is tile-shaped. The angle of the large-sized permanent magnets is 60 degrees, and the angle of the small-sized permanent magnets is 30 degrees. Optionally, the width of the permanent magnets corresponds to the width of the tooth columns of the outer yoke, and the thickness is determined according to the designed magnetic flux. The relationship between the total magnetic flux Φ and the thickness h of the permanent magnets is where B r is the remanence, and θ is the angle of the permanent magnets. The relational expression among the axial length l of the permanent magnets, the number of groups n arrayed along the axial direction, and the mover stroke x is where l W is the axial length of the stator, and k is the distance between the two outer stator groups and the inner yoke.

[0007] Crossbeam plates are provided at both ends of the inner cavity of the magnetic frame. A boss is provided above the crossbeam plates for fixing and locking the resonant spring.

[0008] The outer stator group is composed of two sets of outer stators. The outer stator includes an outer yoke, and windings respectively wound on a coil frame and the outer yoke. Further, the outer yoke is a core with a double C-shaped structure. Two double C-shaped structures are arrayed in the circumferential direction. When installed, the two outer yokes are separated by 30 degrees and aligned at both ends. Optionally, for the double C-shaped structure core with an angle of 150 degrees, the angles of the tooth columns are all 30 degrees, and there is a 1-mm rounded corner at the edge of each tooth column.

[0009] The set of outer stators includes the two sets of windings wound on the coil formers with opposite winding directions and the two sets of windings wound on the intermediate tooth columns with opposite winding directions; the windings fixed on the outer sides of the tooth columns (13-1) and (13-5) and the windings wound on the tooth columns (13-2) and (13-6) are wound in the same direction, and the windings wound on the tooth columns (13-3) and (13-7) and the windings fixed on the outer sides of the tooth columns (13-4) and (13-8) are wound in the opposite direction to the above; further, the coils wound on the intermediate tooth columns (13-2), (13-3), (13-6), and (13-7) of the outer yoke magnetize the intermediate tooth columns (13-2), (13-3), (13-6), and (13-7), and the magnetization intensity of the outer tooth columns is relatively weaker than that of the intermediate tooth columns (13-2), (13-3), (13-6), and (13-7). The magnetization intensity of the outer tooth columns (13-1), (13-4), (13-5), and (13-8) is strengthened by the coils fixed on the outer tooth columns (13-1), (13-4), (13-5), and (13-8) of the outer yoke (13), ensuring that the magnetic fluxes of the tooth columns forming the magnetic circuit are equal; optionally, the windings are connected in series or in parallel, and the leads of the windings first run through the grooves where the left and right end plates contact the outer yoke, and then the wires are led out from the edge grooves of the left and right baffles.

[0010] The inner yoke is composed of two semi-“I”-shaped iron cores, and its axial length is slightly longer than that of the outer yoke; further, when the inner yoke is installed, it is coaxial with the outer stator group, and the positions of the openings on the inner yoke correspond to the windings wound on the coil former, and the two end faces are aligned; optionally, the two ends of the inner yoke are provided with threads and are matched with the left and right end plates.

[0011] Further, the sizes of the left and right end plates, the positions where the threads are provided, and the sector holes are determined according to the design dimensions of the motor and the distribution positions of the coils. When installed, the sector holes correspond to the coils for the purpose of heat dissipation. Six round holes are distributed at the edges of the left and right end plates for fixing the outer stator group, and threaded holes are provided at the axes of the left and right end plates for installing the inner yoke.

[0012] Further, a fixing device is provided in the middle of the front and rear frames. Circular grooves are provided on the inner sides of the top plates on both sides of the frames for locking the resonance springs. Threaded holes are distributed at the edges of the front and rear frames, and the front and rear frames are fixedly connected by bolts; the outer stator group, the inner yoke installed inside the outer stator group, and the mover installed between the outer stator group and the inner yoke are installed on the front and rear frames through the fixing device; the resonance springs are fixed and locked in the bosses on the cross beam plates of the magnetic frame and the circular grooves of the front and rear frames.

[0013] Thus, the multi-magnetic-circuit moving magnetic linear oscillating motor of the present invention can at least have the following effects:

[0014] 1. In the multi-magnetic circuit moving magnet type linear oscillating motor of the present invention, the two coils wound around the two tooth columns in the middle of the outer yoke mainly magnetize the two middle tooth columns, and the magnetization intensity of the outer tooth columns is relatively weaker than that of the two middle tooth columns. The magnetization intensity of the outer tooth columns is enhanced by the coils fixed on the outer tooth columns of the outer yoke, ensuring that the tooth columns forming the magnetic circuit have equal magnetic fluxes passing through them, making the motor run smoothly and the electromagnetic force output stable.

[0015] 2. The outer yoke is a core with a double-C structure and is arranged in two arrays along the circumferential direction, with an angle of 30 degrees between them; the angle of the outer tooth columns of the 150-degree sector-shaped double-C core is 30 degrees, which "plans" the direction of the magnetic circuit, reducing the possibility of magnetic leakage, and there are 1 mm rounded corners on the sides of the tooth columns, avoiding magnetic saturation caused by the tip parts.

[0016] 3. The same-angle, tile-shaped permanent magnets matching the outer tooth columns enable most of the magnetic flux of the magnetic circuit to pass perpendicularly through the arc surface of the permanent magnets, increasing the magnetic flux passing through the permanent magnets, improving the utilization rate of the permanent magnets, increasing the electromagnetic force, and making the motor run more smoothly.

[0017] 4. The magnetic circuit forms a complete closed magnetic circuit through the permanent magnets, the outside of the double-C core, the tooth columns of the double-C core, the semi-“I”-shaped core, and the air gap. When the mover moves, it does not exceed the magnetic field range, that is, the air gap length connected to the tooth columns and permanent magnets of the double-C core does not change, and the magnetic resistance does not increase. While the magnetic circuit is complete, the magnetic flux passing through the magnetic circuit does not change, making the electromagnetic output force stable and the motor performance reliable.

[0018] 5. The main losses of the motor are generated by the coils. Therefore, the coils are the main heat sources of the motor. The heat causes the temperature inside the motor to rise through heat transfer, resulting in a weakening of the magnetism of the permanent magnets and a change in the magnetic saturation point of the yoke, making the magnetic circuit unstable; the windings wound on the coil frame are directly in contact with the air, and the heat is directly transferred to the environment through convective heat transfer; the windings wound on the tooth columns transfer the heat to the windings wound on the coil frame and the outer yoke through heat transfer, and then to the environment through convective heat transfer. Only a small part of the heat remains inside the motor, and the temperature change is small. The magnetic circuit is stable during the operation of the motor, and the electromagnetic thrust output is stable. Description of the Drawings

[0019] Figure 1 Schematic diagram of a quarter of the overall structure of the multi-magnetic circuit moving magnet type linear oscillating motor.

[0020] Figure 2 Left view of the internal structure of the multi-magnetic circuit moving magnet type linear oscillating motor.

[0021] Figure 3(a) Top view of the outer yoke of the multi-magnetic circuit moving magnet type linear oscillating motor.

[0022] Figure 3(b) Three-dimensional schematic diagram of the outer yoke of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0023] Figure 4 Three-dimensional schematic diagram of the magnetic frame of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0024] Figure 5 Three-dimensional schematic diagram of the inner yoke of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0025] Figure 6 Three-dimensional schematic diagram of the end cover of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0026] Figure 7 Schematic diagram of the superimposed magnetic field waveform of the energized winding and the permanent magnet of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0027] Figure 8 Schematic diagram of the equivalent magnetization current of the permanent magnet of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0028] Figure 9 Schematic diagram of the magnetization intensity of the tooth column by the winding wound on the middle tooth column of the outer yoke of the multi-magnetic circuit moving-magnet linear oscillating motor.

[0029] Figure 10 Electromagnetic force of the multi-magnetic circuit moving-magnet linear oscillating motor for theoretical calculation of different permanent magnet array groups.

[0030] Figure 11(a) Schematic diagram of the magnetic flux flow direction of the magnetic circuit when the multi-magnetic circuit moving-magnet linear oscillating motor is energized with a positive current.

[0031] Figure 11(b) Schematic diagram of the magnetic flux flow direction of the magnetic circuit when the multi-magnetic circuit moving-magnet linear oscillating motor is energized with a negative current.

[0032] 1. Front frame; 2. Guide shaft; 3. Rear frame; 4. Left end plate; 5. Winding wound on the coil holder; 6. Inner yoke; 7. Fixing device; 8. Magnetic frame; 9. Right end plate; 10. Resonant spring; 11. Large-sized permanent magnet; 12. Small-sized permanent magnet; 13. Outer yoke; 14. Winding wound on the tooth column; 15. Coil holder; 16. Outer stator; 17. Rotor. Specific implementation mode

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.

[0034] It should be noted that all directional indications (such as outside, inside, left, right, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. Among them, "left" corresponds to Figure 1 the left side in Figure 1 , and "right" corresponds to Figure 8 the right side in

[0035] . Refer to Figure 1 to Figure 1 Figure 1(b) for a detailed description of the multi-magnetic-circuit moving-magnet linear oscillating motor of the present invention.

[0036] As Figure 1 and Figure 2 shown, the present invention provides a multi-magnetic-circuit moving-magnet linear oscillating motor, including: front and rear frames 1, 3, an outer stator group fixing device 7 provided at the middle position between the front and rear frames, an outer stator group installed on the outer stator group fixing device 7, an inner magnetic yoke 6 installed inside the outer stator group, and a mover 17 installed between the outer stator group and the inner magnetic yoke 6; the outer stator group, the mover 17, and the inner magnetic yoke 6 are all coaxially installed.

[0037] A fixing device 7 is provided in the middle of the front and rear frames 1, 3. Circular grooves are provided on the inner sides of the two side plates of the frames for locking the resonance springs 10. Threaded holes are distributed on the edges of the front and rear frames 1, 3, and the front and rear frames 1, 3 are fixedly connected by bolts; the outer stator group, the inner magnetic yoke 6 installed inside the outer stator group, and the mover 17 installed between the outer stator group and the inner magnetic yoke 6 are installed on the front and rear frames through the fixing device 7; the resonance springs 10 are fixed and locked in the convex platforms of the cross beam plates of the magnetic frame 8 and the circular grooves of the front and rear frames 1, 3.

[0038] As Figure 2 shown, the outer stator group is composed of two sets of outer stators 16; the outer stator 16 includes an outer magnetic yoke 13, two sets of windings 5 wound on the coil frames, and two sets of windings 14 wound on the tooth columns of the outer magnetic yoke.

[0039] As shown in Figures 3(a) and 3(b), the outer magnetic yoke 13 is a core with a double C-shaped structure. The cores with a double C-shaped structure are arranged in an array of two in the circumferential direction, and the two cores are separated by 30 degrees;

[0040] The outer diameter of the fan-shaped double C-shaped structure iron core with an angle of 150 degrees is 125 mm, the inner diameter is 60 mm, the outer diameter of a single C-shaped part is 100 mm, the inner diameter is 60 mm, and the angle is 60 degrees, forming tooth grooves. The angle of the fan shape, the inner and outer diameters of the fan shape, and the size of the tooth grooves can be appropriately adjusted according to the size of the motor to be manufactured, the magnitude of the magnetic flux density, the required electromagnetic force, the number of turns of the coil, etc.; according to the formula, the tooth column thickness of the double C-shaped structure is calculated to be 12 mm each, and the electromagnetic force output is stable and maximum. The formula for calculating the tooth column thickness is as follows.

[0041]

[0042] In the formula, τ is the center distance between two permanent magnets, that is, the pole pitch, and K is the tooth width coefficient.

[0043] The angles of the outer tooth columns 13-1 and 13-4 of the double C-shaped structure iron core are 30 degrees, and the tooth groove angle in the middle of the tooth columns 13-2 and 13-3 is 60 degrees. There is a 1-mm fillet at the edge of each tooth column to prevent the magnetic saturation point from appearing at the tip of the tooth column and making the magnetic circuit unstable.

[0044] In the present invention, the double C-shaped iron core 13 is a magnetic conduction component, which can be made by stacking silicon steel sheets along the axial direction or can be shaped using a composite magnetic conduction material. The inner and outer diameters of the double C-shaped structure are determined according to the size of the linear motor to be manufactured and the axial length l fe is related to the stroke of the mover and satisfies the following formula.

[0045] l fB >X + 2l m

[0046] A set of outer stators 16 includes the two groups of windings 5 wound on the coil frames with opposite winding directions and the two groups of windings 14 wound on the middle tooth columns with opposite winding directions.

[0047] The windings fixed to the outer sides of the tooth columns 13-1 and 13-5 and the windings wound around the tooth columns 13-2 and 13-6 are wound in a clockwise direction, and the windings wound around the tooth columns 13-3 and 13-) and the windings fixed to the outer sides of the tooth columns 13-4 and 13-8 are wound in a counterclockwise direction; the coils wound around the middle tooth columns (13-2)(13-3)(13-6) and (13-7) of the outer yoke are magnetized for the middle tooth columns 13-2)(13-3)(13-6) and (13-7), and the magnetization intensity of the outer tooth columns is relatively weaker than that of the middle tooth columns 13-2)(13-3)(13-6) and (13-7). The magnetization intensity of the outer tooth columns (13-1)(13-4)(13-5) and (13-8) of the outer yoke (13) is strengthened by the coils fixed thereto, ensuring that the tooth column magnetic fluxes forming the magnetic circuit are equal.

[0048] The windings are connected in series or parallel. The leads of the windings first run through the grooves where the left and right end plates 4 and 9 are in contact with the outer yoke 13, and then the wires are led out from the edge grooves of the left and right baffles 4 and 9.

[0049] The mover 17 is composed of a magnetic frame 8 and large and small permanent magnets 11 and 12. The large and small permanent magnets 11 and 12 are embedded in the magnetic frame 8 and installed between the outer stator group and the inner yoke 6. The air gap length between the mover 17 and them is between 0.5 and 1 mm.

[0050] There are two types of permanent magnets specified. The material used for the permanent magnets is neodymium iron boron. The permanent magnets are radially magnetized and arranged in the circumferential direction in the order of small, large, small, small, large, small. The permanent magnets are arranged with a single N and S pole. The large permanent magnet 11 is installed corresponding to the two middle tooth columns of the outer yoke 13, and the small permanent magnet 13 is installed corresponding to the two outer tooth columns of the outer yoke;

[0051] The large and small permanent magnets 11 and 12 are in the shape of tiles. The angle of the large permanent magnet 11 is 60 degrees, and the angle of the small permanent magnet 12 is 30 degrees; the width of the permanent magnet corresponds to the width of the tooth columns of the outer yoke 13, and the thickness of the permanent magnet is 3 mm, and the magnetic flux The relationship with the thickness h of the permanent magnet.

[0052]

[0053] In the formula B r is the remanence, and θ is the angle of the permanent magnet.

[0054] The axial length of each permanent magnet is 13 mm, and four groups are evenly arrayed with a 3-mm interval between each group of permanent magnets. The mover stroke is designed to be 20 mm. Derive the relationship among the axial length lm of the permanent magnet, the number of groups t arrayed along the axis, and the mover stroke x.

[0055]

[0056] In the formula, l w is the axial length of the stator, and k is the distance between the two outer stators 16 and the inner yoke 13.

[0057] As Figure 4 shown, the magnetic frame 8 is made of non-magnetic material (such as aluminum alloy). Cross beam plates are provided at both ends of the inner cavity of the magnetic frame. A boss is provided above the cross beam plates for fixing and locking the resonant spring. The cross beam plates are connected to the magnetic frame by welding.

[0058] As Figure 5 shown, the inner yoke 6 is composed of two semi-“I”-shaped iron cores. The outer diameter of the semi-“I”-shaped iron core is 52 mm, the thickness is 8 mm, and it is 5 mm longer than the axial length of the outer yoke 13.

[0059] The “I”-shaped hole of the inner yoke 6 is cut by a sector with an outer diameter of 52 mm and an angle of 15 degrees. During installation, it is coaxial with the outer stator group. The position of the hole opening of the inner yoke 6 corresponds to the winding wound on the coil bobbin, and the distance between the two end faces is 5 mm.

[0060] Threads are provided at both ends of the inner yoke 6 with a thread length of 5 mm. The manufacturing material of the inner yoke 6 is the same as that of the outer yoke 13.

[0061] As Figure 6 shown, the outer diameters of the left and right end plates 4 and 9 are 125 mm, the inner diameters are 52 mm, and the thickness is 5 mm. Sector-shaped through holes are provided at the winding distribution positions. The sector holes correspond to the windings wound on the middle tooth column of the outer yoke 13, with an outer diameter of 100 mm, an inner diameter of 60 mm, and an angle of 60 degrees. The sector holes also correspond to the windings wound on the coil bobbin 15, with an outer diameter of 100 mm, an inner diameter of 60 mm, and an angle of 30 degrees. Six round holes with a hole diameter of 6 mm are distributed at the edges of the left and right end plates 4 and 9 for fixing the outer stator group. A threaded hole with a diameter of 52 mm is provided at the axis of the end plates for installing the inner yoke 6. The manufacturing materials of the left and right end plates 4 and 9 are non-magnetic materials.

[0062] Figures (7) and (10) are schematic diagrams of the superposition of the alternating magnetic fields of the coil and the permanent magnet and the schematic diagram of the magnetic flux flow direction of the magnetic circuit. The permanent magnet adopts a single N, S pole alternating arrangement method. Each two adjacent permanent magnets can form a closed magnetic circuit. One of the magnetic circuits starts from the 13th tooth column 13-2 of the outer yoke, passes through the outer column of the outer yoke 13, the tooth column 13-1, the air gap, and the inner yoke 6 to form a closed magnetic circuit. The magnetic flux φ provided by each permanent magnet outward m The calculation formula is as follows.

[0063]

[0064] In the formula, r1 is the mean diameter of the permanent magnet, and θ is the arc surface angle of the permanent magnet.

[0065] The magnetic conductance P of the permanent magnet m0 Is proportional to the arc surface angle θ of the permanent magnet and inversely proportional to the thickness of the permanent magnet. The calculation formula is as follows.

[0066]

[0067] In the formula, μ0 is the air magnetic permeability, and μ r Is the relative magnetic permeability of the permanent magnet.

[0068] The magnetic flux of the permanent magnet passes through the air gap to the outer tooth column of the outer yoke 13. There will be a magnetic resistance in the air gap, which causes a part of the magnetic flux to be lost. The air gap magnetic resistance is proportional to the air gap length and the thickness of the permanent magnet, and inversely proportional to the axial length and the arc surface angle of the permanent magnet. The calculation formula is as follows.

[0069]

[0070] Due to the formula of the magnetic potential formed by the permanent magnet.

[0071]

[0072] Assume that the iron core of the outer yoke 13 does not generate magnetic voltage drop, and there is a magnetic resistance at the air gap. Then the magnetic voltage drop of the permanent magnet is all at the air gap. Therefore, the magnetic potential of the permanent magnet also satisfies the formula.

[0073] F m =Φ z R g

[0074] Through the above formulas, it can be sorted out that.

[0075]

[0076] In the present invention, the windings wound around the two middle tooth columns 13-2, 13-3, 13-6, and 13-7 of the outer yoke 13 mainly magnetize the middle tooth columns 13-2, 13-3, 13-6, and 13-7, and weaken the magnetization intensity of the tooth columns 13-1, 13-4, 13-5, and 13-8 on the outer side of the outer yoke 13, so that the magnetic flux of its magnetic circuit is less than that of the middle tooth columns. Therefore, four groups of coils are added and fixed at the positions of the outer tooth columns 13-1, 13-4, 13-5, and 13-8 of the outer yoke. By changing the number of turns of the coils, the magnetization intensity of the tooth columns of the outer yoke of the motor is balanced, ensuring the balance of the magnetic flux of each magnetic circuit. On the premise that the magnetic circuit does not reach magnetic saturation, the magnetic flux is increased on the basis of the magnetic flux of the original magnetic circuit, so that the magnetic flux density is increased, the electromagnetic force is increased, and the utilization rate of the permanent magnet is increased. The coils form an expression of the magnetic flux density.

[0077]

[0078]

[0079] In the formula, N' w is the number of turns of the coil wound around the coil holder, N w is the number of turns of the coil of the double C-shaped middle tooth column, and I is the current with the unit of A.

[0080] The process of magnetizing the coil is as Figure 8 shown, which is a simplified schematic diagram of the magnetization intensity of the tooth column after the coil is energized, and the formula is as follows.

[0081]

[0082] The above formulas are integrated to obtain.

[0083]

[0084] From Figure 9 it can be seen that within one cycle, the magnetization intensity of the outer tooth columns by the windings wound around the middle tooth columns is slightly less than the magnetization intensity of the two middle tooth columns. That is, when forming a closed magnetic circuit, the magnetic fluxes of each adjacent tooth column are not equal, making the magnetic circuit of the outer tooth columns unstable and resulting in a decrease in the utilization rate of the permanent magnet.

[0085] The windings wound around the coil holder are fixed on the outer tooth columns of the outer yoke to enhance the magnetization intensity of the outer tooth columns. The number of turns of the other two groups of coils needs to satisfy the following relationship.

[0086]

[0087] The magnetic potential generated by the windings wound around the middle tooth columns is calculated as follows.

[0088] F c = N wi

[0089] The magnetomotive force generated by the winding wound around the bobbin is calculated as follows.

[0090]

[0091] The electromagnetic thrust of the transverse magnetic field magnetic flux is caused by the interaction between the superimposed magnetic field formed by the reaction magnetic field formed by the energized coil and the constant magnetic field of the permanent magnet and the mover. The permanent magnet is equivalent to the magnetic field generated by the magnetizing current, and the magnetic flux linkage formed inside the motor can be equivalent to the magnetic flux of the magnetic circuit, as Figure 9 shown as the equivalent magnetizing current of the permanent magnet.

[0092] Through the theory of co-energy, the electromagnetic force is obtained by taking the partial derivative of the co-energy with respect to displacement.

[0093]

[0094] W (i,x) is the co-energy at the air gap, which is a function of the winding current and the mover position.

[0095] The relationship between co-energy and magnetic flux linkage

[0096]

[0097] where Φ(i, x) = Φ m + Φ c Φ m is the magnetic flux linkage of the permanent magnet, and Φ c is the magnetic flux linkage of the winding.

[0098] To obtain the electromagnetic force expression, it is necessary to find the partial derivative of the magnetic flux linkage with respect to displacement and the derivation is as follows: When the mover is at the initial position, it is assumed that the magnetization intensity of the winding carrying current on the teeth of the outer yoke is the same, that is, the magnetic flux through each tooth is equal, so that the magnetization polarity of the outer teeth close to the outer yoke is the same as that of the permanent magnet, then the magnetism of the permanent magnet on the outer teeth is suppressed and the magnetism of the middle permanent magnet is enhanced. At this time, the magnetic flux linkage intensity formed becomes twice the original, and the magnetic flux of the teeth also becomes twice the original.

[0099] The change formula of magnetic flux linkage.

[0100]

[0101] where l is the length of the equivalent coil winding and △x is the displacement change of the mover.

[0102] The above formula is sorted out as.

[0103]

[0104] Where m is the number of tooth columns. Theoretically, the number of turns of the coil of the equivalent small-sized permanent magnet is twice that of the equivalent large-sized permanent magnet. By deriving that the electromagnetic force is a constant value, the magnitude of the electromagnetic force is related to the magnetic density, current at the air gap, and the length of the equivalent coil winding, and is independent of displacement. The electromagnetic force output is stable during the movement of the mover.

[0105] According to the present invention, a multi-magnetic-circuit moving-magnet linear oscillating motor is designed. Based on the derivation of the electromagnetic force formula, the length of the permanent magnet and the number of groups arranged axially are determined. The derivation formula is as follows.

[0106]

[0107] As Figure 10 shown, under the condition of limiting the length of the mover, when the axial length of the permanent magnet increases, the electromagnetic force first increases and then decreases with the increase of the length of the permanent magnet. It can be obtained from the data graph that when the axial length of the permanent magnet is 12 mm and 4 groups are arranged axially, the electromagnetic force reaches a peak value, reducing the usage amount of the permanent magnet by 12.7%, improving the efficiency of the permanent magnet, and reducing the mass of the mover.

[0108] Figures 11(a) and 11(b) are schematic diagrams of the magnetic flux flow directions of the magnetic circuit when currents in different directions are applied. It can be seen from Figures 11(a) and 11(b) that when currents in different directions are applied, the magnetic flux flow direction of the magnetic circuit changes, and the electromagnetic force direction changes accordingly, indicating that the principle of this motor is feasible and the structure is reliable.

[0109] For the multi-magnetic-circuit moving-magnet linear oscillating motor of the present invention, by re - "formulating" the number of groups of the permanent magnet array and the shape of the yoke, the direction and number of the magnetic circuit are adjusted. On the premise that the magnetic circuit does not reach the magnetic saturation point, by adding coils to the tooth columns on the outer side of the outer yoke, the magnetization intensity of the tooth columns on the outer side of the outer yoke is enhanced and the magnetic flux between each tooth column is basically equal, improving the electromagnetic force and the utilization rate of the permanent magnet, reducing the mass of the mover and the waste of materials. Through theoretical analysis, the principle of the motor is feasible, the structure is reliable, and it meets the requirements for improving product performance.

[0110] The above are only the preferred embodiments of the present invention, and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A multi-magnetic circuit moving-magnet linear oscillating motor, characterized in that, Comprising: Front and rear frames (1)(3), an outer stator group fixing device (7) disposed at an intermediate position between the front and rear frames (1)(3), an outer stator group installed on the outer stator group fixing device (7), an inner yoke (6) installed inside the outer stator group, and a rotor (17) installed between the inner yokes (6) of the outer stator group; the outer stator group is composed of two sets of outer stators (16), and the outer stator (16) includes an outer yoke (13), two coils (14) respectively wound around two tooth columns in the middle of the outer yoke (13) and with opposite winding directions. The two coils are wound on a coil frame and have opposite winding directions, and are respectively fixed on the outer sides of the outer tooth columns of the outer yoke (13) to enhance the magnetization intensity of the outer tooth columns and ensure that the magnetic fluxes of each tooth column forming the magnetic circuit are equal; the rotor (17) is composed of a magnetic frame (8) and permanent magnets (11)(12), and the permanent magnets (11)(12) are installed corresponding to the tooth columns of the outer yoke (13); the outer stator group, the rotor (17), and the inner yoke (6) are all coaxially installed; an alternating current is applied to the coils, and the rotor (17) reciprocates in the alternating magnetic field formed by the permanent magnets and the coils; the rotor (17) is composed of a magnetic frame (8) and permanent magnets (11)(12), and the permanent magnets (11)(12) are embedded in the magnetic frame (8) and installed between the outer stator group and the inner yoke (6); there are two types of the permanent magnets (11)(12), the magnetization directions of the permanent magnets (11)(12) are radial, and the circumferential direction is arranged in the order of small, large, small, small, large, small. The large and small types of permanent magnets (11)(12) present a single N, S pole arrangement, and four groups are evenly arrayed along the axial direction. The large-sized permanent magnets (11) are installed corresponding to the two tooth columns in the middle of the outer yoke (13), and the small-sized permanent magnets (12) are installed corresponding to the outer tooth columns of the outer yoke (13); the shapes of the permanent magnets (11)(12) are tile-shaped, the angle of the large-sized permanent magnets (11) is 60 degrees, the angle of the small-sized permanent magnets (12) is 30 degrees, the widths of the permanent magnets (11)(12) correspond to the widths of the tooth columns of the outer yoke (13), and the thickness of the permanent magnets (11)(12) is determined according to the designed magnetic flux, and the total magnetic flux The relationship with the thickness h of the permanent magnet is where B r where \(R\) is the residual magnetism and \(\theta\) is the angle of the permanent magnet; the relationship among the axial length \(l\) of the permanent magnet, the number of groups \(n\) arrayed along the axis, and the mover stroke \(x\) is \(x = n\cdot l - 2k\), where \(l\) is the axial length of the stator and \(k\) is the distance between the two outer stator groups and the inner yoke; crossbeam plates are provided at both ends of the inner cavity of the magnetic frame (8), and bosses are provided above the crossbeam plates for fixing and locking the resonance spring (10); the outer stator group is composed of two sets of outer stators (16); the outer stator includes an outer yoke (13), two sets of coils (5) wound on a coil holder in opposite directions, and two sets of coils (14) wound on the middle tooth columns of the outer yoke (13) in opposite directions; the outer yoke (13) is a double-C-shaped iron core with an angle of 150 degrees, and two double-C-shaped iron cores are arrayed in the circumferential direction, with a 30-degree interval between the two installed outer yokes; the angles of the tooth columns are all 30 degrees, the two ends are aligned, and the interval between the two middle tooth columns is 60 degrees. There is a 1-mm rounded corner at the edge of each tooth column; along the inner circumference of the first double-C-shaped iron core, there are tooth columns one to four (13-1)(13-2)(13-3)(13-4) in the clockwise direction, and along the inner circumference of the second double-C-shaped iron core, there are tooth columns five to eight (13-5)(13-6)(13-7)(13-8) in the clockwise direction. Tooth column four and tooth column five are adjacent, and tooth column one and tooth column eight are adjacent; one set of the outer stator (16) includes the two sets of coils (5) wound on the coil holder in opposite directions and the two sets of coils (14) wound on the middle tooth columns in opposite directions; the coils fixed on the outer sides of the tooth columns (13-1) and (13-5) and the coils wound on the tooth columns (13-2) and (13-6) are wound in the same direction, and the coils wound on the tooth columns (13-3) and (13-7) and the coils fixed on the outer sides of the tooth columns (13-4) and (13-8) are wound in the opposite direction to the above-mentioned winding direction; the coils wound on the middle tooth columns (13-2)(13-3)(13-6) and (13-7) of the outer yoke magnetize the middle tooth columns (13-2)(13-3)(13-6) and (13-7). The magnetization intensity of the outer tooth columns is relatively weaker than that of the middle tooth columns (13-2)(13-3)(13-6) and (13-7). The magnetization intensity of the outer tooth columns (13-1)(13-4)(13-5) and (13-8) is strengthened by the coils fixed on the outer tooth columns (13-1)(13-4)(13-5) and (13-8) of the outer yoke (13) to ensure that the magnetic fluxes of the tooth columns forming the magnetic circuit are equal; the coils are connected in series or in parallel. The leads of the coils first pass through the grooves where the left and right end plates (4)(9) are in contact with the outer yoke, and then the wires are led out from the edge grooves of the left and right baffles. The shape of the coil winding is fan-shaped.

2. The multi-magnetic circuit moving magnet linear oscillating motor according to claim 1, wherein The inner yoke (6) is composed of two semi-"I"-shaped iron cores, and is slightly longer than the outer yoke in the axial direction; when the "I"-shaped hole of the inner yoke (6) is installed, it is coaxial with the outer stator group, and the position of the hole in the inner yoke (6) corresponds to the coil wound on the coil holder. Threads are provided at both ends of the inner yoke (6) for connection with the left and right end plates (4) and (9).

3. The multi-magnetic-circuit moving-magnet linear oscillating motor according to claim 1, characterized in that, The sizes of the left and right end plates (4) and (9), the threaded portions and the fan-shaped holes are determined according to the motor design dimensions and the distribution positions of the coils (5) and (14). When installed, the fan-shaped holes correspond to the coils for the purpose of heat dissipation. Six round holes are distributed at the edges of the left and right end plates (4) and (9) for fixing the outer stator group, and threaded holes are provided at the axes of the left and right end plates (4) and (9) for installing the inner yoke (6).

4. A multi-magnetic circuit moving-magnet linear oscillating motor according to claim 1, characterized in that, A fixing device (7) is provided in the middle of the front and rear frames (1) and (3). Circular grooves are provided on the inner sides of the top plates on both sides of the front and rear frames (1) and (3) for locking the resonance springs (10). Threaded holes are distributed at the edges of the front and rear frames (1) and (3), and the front and rear frames (1) and (3) are fixedly connected by bolts; the outer stator group, the inner yoke (6) and the rotor (17) are installed on the front and rear frames (1) and (3) through the fixing device (7); the resonance springs (10) are fixed and locked in the convex platforms of the cross beam plates of the magnetic frame (8) and the circular grooves of the front and rear frames (1) and (3).

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