A barrel-type linear motor magnetic levitation permanent magnet speed regulator and speed regulation method

Abstract

The present invention discloses a cylindrical linear motor magnetic levitation permanent magnet speed regulator and a speed regulation method, comprising: a cylindrical linear motor, a radial two-degree-of-freedom hybrid magnetic bearing, a radial-axial three-degree-of-freedom hybrid magnetic bearing, a displacement detection ring, and a cylindrical permanent magnet speed regulator. The linear motor drives the secondary mover to move linearly along the axial direction according to the load signal, thereby driving the linear guide to move axially; since the stators of the two hybrid magnetic bearings and the linear guide are both fixed on the non-magnetic plate, the stators of the two hybrid magnetic bearings will also move axially accordingly, thereby changing the distance between the conductor ring and the permanent magnet ring; in order to ensure that the rotor of the axial three-degree-of-freedom hybrid magnetic bearing is in the axial center position, a method of controlling the current and the suspension force is adopted to make the axial hybrid magnetic bearing in a stable working state. Compared with the prior art, the structure of the present invention is simpler, there is no frictional loss, the service life is long, the loss is small, and the magnetic levitation technology can be adopted at the same time to make its speed regulation more accurate.

Description

Technical Field

[0001] The present invention relates to the field of permanent magnet speed regulation systems, and particularly to a cylindrical linear motor magnetic levitation permanent magnet speed regulator and a speed regulation method. Background Art

[0002] With the continuous development of magnetic levitation technology and permanent magnet speed regulator technology, the magnetic levitation permanent magnet speed regulator technology has also been continuously broken through and innovated. It combines the friction reduction and suspension characteristics of magnetic levitation technology, as well as the high-efficiency speed regulation advantages of permanent magnet speed regulators, achieving more efficient and energy-saving motor speed regulation. Currently, researchers are working on improving the speed regulation range, efficiency, stability, and reliability of magnetic levitation permanent magnet speed regulators. In addition, by introducing intelligent control technology, the automation and intelligent control of magnetic levitation permanent magnet speed regulators are realized, enabling them to achieve the optimal speed regulation effect under various working conditions.

[0003] Traditional speed regulators will generate a large amount of losses due to the mutual contact between their structures, so their efficiency will inevitably decrease; and due to the mutual contact, a large amount of heat will be generated, and the damage to the structure is also unpredictable; the speed regulation range of traditional motor speed regulation methods is also small.

[0004] A cylindrical linear motor magnetic levitation permanent magnet speed regulator and a speed regulation method designed by the present invention can make its structure simpler, without friction loss, the motor has a long service life, small loss, and can simultaneously adopt magnetic levitation technology to make its speed regulation accuracy higher. Summary of the Invention

[0005] Object of the Invention: Aiming at the problems pointed out in the background art, a cylindrical linear motor magnetic levitation permanent magnet speed regulator and a speed regulation method proposed by the present invention can solve the problem that existing motors generate a large amount of losses and have low efficiency due to the mutual contact between their structures.

[0006] Technical Solution: The present invention provides a cylindrical linear motor magnetic levitation permanent magnet speed regulator, including a cylindrical linear motor, a radial two-degree-of-freedom hybrid magnetic bearing, a radial-axial three-degree-of-freedom hybrid magnetic bearing, a cylindrical permanent magnet speed regulator, a housing, and an end cover; the radial two-degree-of-freedom hybrid magnetic bearing and the radial-axial three-degree-of-freedom hybrid magnetic bearing are located inside the cylindrical linear motor, and two displacement detection rings are respectively placed on both sides; the cylindrical permanent magnet speed regulator is placed on one side of the cylindrical linear motor and is connected to the load shaft;

[0007] The primary stator of the cylindrical linear motor is fixed on the housing, and its three-phase windings and permanent magnets are respectively bonded to the primary stator and the metal plate; the secondary mover composed of the permanent magnet and the metal plate is fixed on the non-magnetic plate;

[0008] The radial stator of the radial two-degree-of-freedom hybrid magnetic bearing and the axial stator of the radial-axial three-degree-of-freedom hybrid magnetic bearing are both fixed on the inner side of the non-magnetic plate;

[0009] The rotor A of the radial two-degree-of-freedom hybrid magnetic bearing and the rotor B of the radial-axial three-degree-of-freedom hybrid magnetic bearing are both fixed on the rotating shaft; the winding A of the radial two-degree-of-freedom hybrid magnetic bearing is wound on the radial stator, and the winding B of the radial-axial three-degree-of-freedom hybrid magnetic bearing is wound on the axial stator.

[0010] Further, the tubular permanent magnet speed regulator includes an outer cylindrical body and an inner cylindrical body; the left side of the outer cylindrical body is connected to the rotating shaft, and a conductor ring is fixed on the right side of the inner cavity of the outer cylindrical body; the right side of the inner cylindrical body is connected to the load shaft, and a permanent magnet ring is fixed on the left outer wall of the inner cylindrical body, and the conductor ring is directly opposite to the permanent magnet ring.

[0011] Further, the inner cylindrical body of the tubular permanent magnet speed regulator passes through the end cover through a ball bearing and is connected to the load shaft.

[0012] The present invention also discloses a speed regulation method based on the above-mentioned tubular linear motor magnetic levitation permanent magnet speed regulator, including the following steps:

[0013] Step (1): When the tubular linear motor detects a change in the load information, when three-phase alternating current is applied to the three-phase windings of the tubular linear motor, a traveling wave magnetic field is formed around the primary stator, and a permanent magnet magnetic field is generated on the permanent magnet of the secondary mover.

[0014] Step (2): The magnetic field generated by the induced current on the secondary mover interacts with the traveling wave magnetic field of the primary stator to generate a thrust that pushes the secondary mover to move axially along the non-magnetic plate.

[0015] Step: The secondary mover moves axially under the action of the thrust, and at the same time, the stators of the radial two-degree-of-freedom hybrid magnetic bearing and the radial-axial three-degree-of-freedom hybrid magnetic bearing move axially accordingly, and the rotor B of the radial-axial three-degree-of-freedom hybrid magnetic bearing is not in its central position and is displaced.

[0016] Step (3): The axial displacement of the rotating shaft is detected by the displacement detection ring and fed back to the radial-axial three-degree-of-freedom hybrid magnetic bearing, and the current of the winding B of the radial-axial three-degree-of-freedom hybrid magnetic bearing is adjusted to generate a corresponding axial suction force to drive the rotating shaft to move axially and make the rotor B return to the central position; among them, the winding B includes a radial suspension winding and an axial suspension winding, the radial suspension winding controls the radial suspension of the rotating shaft with the radial two-degree-of-freedom radial magnetic bearing, and the axial suspension winding controls the axial follow-up of the rotor B with the secondary mover.

[0017] Step (4): The tubular permanent magnet speed regulator adjusts the magnetic field meshing area between the conductor ring and the permanent magnet ring according to the feedback amount, so that the rotor B is always in the central position of the radial-axial three-degree-of-freedom hybrid magnetic bearing.

[0018] Furthermore, the maximum axial displacement of the cylindrical permanent magnet speed regulator is 10 mm, and the axial air gap length of the radial-axial three-degree-of-freedom hybrid magnetic bearing is 0.5 mm. When the movement of the secondary mover is less than 0.5 mm of the axial air gap of the radial-axial three-degree-of-freedom hybrid magnetic bearing, the rotating shaft is adjusted in real time to follow the movement.

[0019] Furthermore, when the magnetic field meshing area between the conductor ring and the permanent magnet ring becomes larger, the transmitted torque becomes larger and the rotational speed of the load becomes higher; when the magnetic field meshing area between the conductor ring and the permanent magnet ring becomes smaller, the transmitted torque becomes smaller and the rotational speed of the load becomes lower.

[0020] Furthermore, the relationship between the maximum axial suspension force of the radial-axial three-degree-of-freedom hybrid magnetic bearing and the maximum thrust F 推 of the cylindrical linear motor and the load force F 负 is determined as follows:

[0021] Select the permanent magnet material of the radial-axial three-degree-of-freedom hybrid magnetic bearing, and determine the air gap saturation magnetic density B s of the radial-axial three-degree-of-freedom hybrid magnetic bearing, and determine the axial air gap length g 轴 ;

[0022] According to the maximum thrust F 推 of the cylindrical linear motor and the load force F 负 , then the maximum axial suspension force F 轴 of the radial-axial three-degree-of-freedom hybrid magnetic bearing = F 推 - F 负 ;

[0023] S 轴 is the pole area of the axial stator of the radial-axial three-degree-of-freedom hybrid magnetic bearing, then the maximum axial suspension force F is determined by 轴 , μ 0 is the vacuum permeability, μ 0 = 4π × 10 -7 H / m.

[0024] Beneficial effects:

[0025] The present invention forms a magnetic suspension permanent magnet speed regulator by combining a hybrid magnetic bearing and a motor drive, reduces the friction between structures, reduces losses, and improves power; and because there is no friction, the modulation speed range will be larger; at the same time, compared with the traditional permanent magnet speed regulator, due to the adoption of more precise magnetic suspension technology, its precision is also improved. Description of the drawings

[0026] Figure 1 is a structural diagram of a magnetic suspension permanent magnet speed regulator of the present invention.

[0027] Among them, 1 - cylindrical linear motor, 2 - three-phase winding, 3 - permanent magnet, 4 - metal plate, 5 - primary stator, 6 - left displacement detection device, 7 - left sensor bracket, 8 - left radial displacement sensor, 9 - displacement detection ring, 10 - radial two-degree-of-freedom hybrid magnetic bearing, 11 - radial stator, 12 - winding A, 13 - rotor A, 14 - radial-axial three-degree-of-freedom hybrid magnetic bearing, 15 - rotor B, 16 - winding B, 17 - axial stator, 18 - right displacement detection device, 19 - axial displacement sensor, 20 - right radial displacement sensor, 21 - tubular permanent magnet speed regulator, 22 - outer cylindrical body, 23 - inner cylindrical body, 24 - ball bearing, 25 - load shaft, 26 - rotating shaft, 27 - end cover, 28 - housing, 29 - non-magnetic plate, 30 - conductor ring, 31 - permanent magnet ring. Specific embodiments

[0028] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be used to limit the protection scope of the present invention.

[0029] Figure 1 It is a structural diagram of a tubular linear motor magnetic levitation permanent magnet speed regulator of the present invention. It includes: a cylindrical linear motor 1, a radial two-degree-of-freedom hybrid magnetic bearing 10, a radial-axial three-degree-of-freedom hybrid magnetic bearing 14, a tubular permanent magnet speed regulator 21, a housing 28 and an end cover 27.

[0030] Among them, the primary stator 5 of the cylindrical linear motor 1 is fixed on the housing 28, and the left radial two-degree-of-freedom hybrid magnetic bearing 10 and the right radial-axial three-degree-of-freedom hybrid magnetic bearing 14 are located inside the cylindrical linear motor 1. Left and right displacement detection devices 6 and 18 are respectively placed on both sides of the two hybrid magnetic bearings.

[0031] The tubular permanent magnet speed regulator 21 is placed on the right side of the cylindrical linear motor 1 and connected to the load shaft 25.

[0032] The three-phase winding 2 and the permanent magnet 3 of the cylindrical linear motor 1 are respectively bonded to the primary stator 5 and the metal plate 4. The secondary mover composed of the permanent magnet 3 and the metal plate 4 is fixed on the non-magnetic plate 29.

[0033] The radial stator 11 of the left radial two-degree-of-freedom hybrid magnetic bearing 10 and the axial stator 17 of the right radial-axial three-degree-of-freedom hybrid magnetic bearing are both fixed on the non-magnetic plate 29. The rotor A 13 of the radial two-degree-of-freedom hybrid magnetic bearing 10 and the rotor B 15 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 are both fixed on the rotating shaft 26. The winding A 12 of the radial two-degree-of-freedom hybrid magnetic bearing 10 is wound around the radial stator 11, and the winding B 16 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 is wound around the axial stator 17.

[0034] The left and right displacement detection devices 6 and 18 are used to detect the displacement between the rotating shaft 26 of the hybrid magnetic bearing and the rotor. They include a displacement detection ring 9, a left radial displacement sensor 8, a right radial displacement sensor 20, and an axial displacement sensor 19. The left radial displacement sensor 8, the right radial displacement sensor 20, and the axial displacement sensor 19 face the displacement detection ring 9 and are respectively used to detect the displacement deviation in the radial and axial directions.

[0035] The barrel-type permanent magnet speed regulator 21 includes an outer cylindrical body 22 and an inner cylindrical body 23. The left side of the outer cylindrical body 22 is connected to the rotating shaft 26. A conductor ring 30 is fixed on the right side of the inner cavity of the outer cylindrical body 22. The right side of the inner cylindrical body 23 is connected to the load shaft 25. The inner cylindrical body 23 passes through the end cover 27 and is connected to the load shaft 25 through a ball bearing 24. A permanent magnet ring 31 is fixed on the left side of the inner cylindrical body 23, and the conductor ring 30 and the permanent magnet ring 31 are in a facing position.

[0036] Its speed regulation method has the following steps:

[0037] Step (1): When the cylindrical linear motor 1 detects a change in the load information, speed regulation starts. When three-phase alternating current is applied to the three-phase windings 2 of the cylindrical linear motor 1, a traveling wave magnetic field will be formed around the primary stator 5, and the permanent magnets of the secondary mover will generate a permanent magnetic field.

[0038] Step (2): The magnetic field generated by the induced current on the secondary mover interacts with the traveling wave magnetic field of the primary stator 5 to generate a thrust that pushes the secondary mover to move axially along the non-magnetic plate 29 below it.

[0039] Step (3): The secondary mover moves axially under the action of the thrust. At the same time, the stators of the radial two-degree-of-freedom hybrid magnetic bearing 10 and the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 will also move axially accordingly, resulting in a change in the axial air gap. At this time, the rotor B15 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 is not in its central position and is displaced.

[0040] Step (4): To ensure that the rotor B15 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 returns to the center position of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14, it is necessary to adjust the current in the winding B16 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 to generate a corresponding axial thrust to drive the axial movement of the rotating shaft, so that the rotor B15 returns to the center position. The axial displacement of the rotating shaft 26 is detected by the displacement detection ring and fed back to the radial-axial three-degree-of-freedom hybrid magnetic bearing 14. The current in the winding B16 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 is adjusted to generate a corresponding axial suction force to drive the axial movement of the rotating shaft 26, so that the rotor B15 returns to the center position. Among them, the winding B16 includes a radial suspension winding and an axial suspension winding. The radial suspension winding controls the radial suspension of the rotating shaft 26 by the radial two-degree-of-freedom radial magnetic bearing 10, and the axial suspension winding controls the axial follow-up of the rotor B15 with the secondary mover.

[0041] Step (5): The barrel-type permanent magnet speed regulator 21 adjusts the magnetic field meshing area between the conductor ring 30 on the outer cylindrical body 22 and the permanent magnet ring 31 on the inner cylindrical body 23 according to the feedback amount, so that the rotor B15 is always in the center position of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14. When the magnetic field meshing area between the conductor ring 30 and the permanent magnet ring 31 becomes larger, the transmitted torque becomes larger and the speed of the load becomes higher; when the magnetic field meshing area between the conductor ring 30 and the permanent magnet ring 31 becomes smaller, the transmitted torque becomes smaller and the speed of the load becomes lower.

[0042] The maximum axial displacement of the barrel-type speed regulator 21 is 10 mm, and the axial air gap length of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 is 0.5 mm. Therefore, to ensure the normal operation of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14, it is necessary to adjust it in real time according to the displacement of the rotating shaft 26 detected by the displacement detection ring 9 and the displacement sensor. When the movement of the secondary mover is less than the axial air gap of 0.5 mm of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14, the rotating shaft 26 is adjusted to follow in real time.

[0043] The maximum axial suspension force of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 and the maximum thrust F of the cylindrical linear motor 1 推 and the load force F 负 The relationship between them is determined as follows:

[0044] Select the permanent magnet material of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14, determine the air gap saturation magnetic density B of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 s , determine the axial air gap length g 轴 , according to the maximum thrust F of the linear motor 推 and the load force F 负 , then the maximum axial suspension force F of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 轴 =F 推-F 负 , S 轴 is the pole area of the axial stator 17 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14, then μ 0 is the vacuum permeability, μ 0 = 4π × 10 -7 H / m.

[0045] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A cylindrical linear motor magnetic suspension permanent magnet speed regulator, characterized in that: The invention comprises a cylindrical linear motor (1), a radial two-degree-of-freedom hybrid magnetic bearing (10), a radial-axial three-degree-of-freedom hybrid magnetic bearing (14), a cylindrical permanent magnetic speed regulator (21), a housing (28) and an end cover (27); the radial two-degree-of-freedom hybrid magnetic bearing (10) and the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) are located inside the cylindrical linear motor (1), and a displacement detection ring is placed on both sides respectively; the cylindrical permanent magnetic speed regulator (21) is placed on one side of the cylindrical linear motor (1) and is connected to a load shaft (25); The primary stator (5) of the cylindrical linear motor (1) is fixed on a housing (28), and the three-phase winding (2) and the permanent magnet (3) are respectively bonded to the primary stator (5) and the metal plate (4); the secondary mover composed of the permanent magnet (3) and the metal plate (4) is fixed on a non-magnetic plate (29); The radial stator (11) of the radial two-degree-of-freedom hybrid magnetic bearing (10) and the axial stator (17) of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) are both fixed on the inner side of the non-magnetic conductive plate (29); The rotor A (13) of the radial two-degree-of-freedom hybrid magnetic bearing (10) and the rotor B (15) of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) are both fixed on a rotating shaft (26); the winding A (12) of the radial two-degree-of-freedom hybrid magnetic bearing is wound on a radial stator (11), and the winding B (16) of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is wound on an axial stator (17).

2. A cylindrical linear motor magnetic suspension permanent magnet speed regulator according to claim 1, characterized in that: The cylindrical permanent magnet speed regulator (21) comprises an outer cylindrical body (22) and an inner cylindrical body (23); the left side of the outer cylindrical body (22) is connected to a rotating shaft (26), and a conductor ring (30) is fixed to the right side of the inner cavity of the outer cylindrical body (22); the right side of the inner cylindrical body (23) is connected to a load shaft (25), and a permanent magnet ring (31) is fixed to the left outer wall of the inner cylindrical body (23), and the conductor ring (30) and the permanent magnet ring (31) are directly opposite to each other.

3. A cylindrical linear motor magnetic suspension permanent magnet speed regulator according to claim 2, characterized in that: The inner cylindrical body (23) of the cylindrical permanent magnet speed regulator (21) is connected to the load shaft (25) through a ball bearing (24) and an end cover (27).

4. A speed regulation method based on the magnetic suspension permanent magnet speed regulator of a cylindrical linear motor according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step (1): When the cylindrical linear motor (1) detects a change in load information, a three-phase alternating current is supplied to the three-phase winding (2) of the cylindrical linear motor (1), thereby forming a traveling wave magnetic field around the primary stator (5), and the permanent magnet on the secondary mover generates a permanent magnetic field; Step (2): the magnetic field generated by the induced current on the secondary mover interacts with the traveling wave magnetic field of the primary stator (5), generating a thrust for pushing the secondary mover to move axially along the non-magnetic conductive plate (29); Step (3): the secondary mover moves axially under the action of the thrust, and at the same time, the stators of the radial two-degree-of-freedom hybrid magnetic bearing (10) and the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) move axially accordingly, and the rotor B (15) of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is not in its center position and is offset; Step (4): the axial displacement of the rotating shaft (26) is detected by a displacement detection ring, and the displacement is fed back to the radial-axial three-degree-of-freedom hybrid magnetic bearing (14), and the current of the winding B (16) of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is adjusted to generate a corresponding axial suction force, thereby driving the rotating shaft (26) to move axially and returning the rotor B (15) to the center position; wherein the winding B (16) includes a radial suspension winding and an axial suspension winding, the radial suspension winding and the radial two-degree-of-freedom hybrid magnetic bearing (10) control the radial suspension of the rotating shaft (26), and the axial suspension winding controls the rotor B (15) to follow the axial movement of the secondary mover; Step (5): The drum-type permanent magnet speed regulator (21) adjusts the magnetic field meshing area between the conductor ring (30) and the permanent magnet ring (31) according to the feedback amount, so that the rotor B (15) is always located at the center position of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14).

5. The speed regulation method according to claim 4, characterized in that: The maximum axial displacement of the cylindrical permanent magnet speed regulator (21) is 10 mm, the axial air gap length of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is 0.5 mm, and when the movement of the secondary mover is less than 0.5 mm of the axial air gap of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14), the rotating shaft (26) is adjusted to follow the movement in real time.

6. The speed regulation method according to claim 4, characterized in that: When the magnetic field meshing area between the conductor ring (30) and the permanent magnet ring (31) increases, the transmitted torque increases and the rotational speed of the load increases; when the magnetic field meshing area between the conductor ring (30) and the permanent magnet ring (31) decreases, the transmitted torque decreases and the rotational speed of the load decreases.

7. The speed regulation method according to claim 4, characterized in that: The maximum axial suspension force of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) and the maximum thrust F of the cylindrical linear motor (1) 推 With load force F 负 The relationship between them is determined as follows: The permanent magnetic material of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is selected, and the air gap saturation magnetic density B of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is determined. s , determine the axial air gap length g 轴 ; Based on the maximum thrust F of the cylindrical linear motor (1) 推 With load force F 负 , then the maximum axial suspension force F of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14) is 轴 =F 推 -F 负 ; S 轴 is the magnetic pole area of ​​the axial stator (17) of the radial-axial three-degree-of-freedom hybrid magnetic bearing (14), then Determine the maximum axial suspension force F 轴 , μ0 is the vacuum permeability, μ0=4π×10 -7 H / m.

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