Cylinder type linear motor magnetic suspension permanent magnet speed regulator and speed regulation method

Abstract

The invention discloses a cylindrical linear motor magnetic suspension permanent magnet speed regulator and a speed regulation method. The cylindrical linear motor magnetic suspension permanent magnet speed regulator comprises 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 rotor to linearly move along the axial direction according to a load signal, so as to drive the linear guide rail to axially move; the two hybrid magnetic bearing stators and the linear guide rail are fixed on the non-magnetic conductive plate, so that the two hybrid magnetic bearing stators can axially move along with the non-magnetic conductive plate, and the distance between the conductor ring and the permanent magnet ring is further changed; in order to ensure that a rotor of the axial three-degree-of-freedom hybrid magnetic bearing is located at the axial central position, the axial hybrid magnetic bearing is in a stable working state by adopting a mode of controlling current and suspension force. Compared with the prior art, the speed regulation device is simpler in structure, free of friction loss, long in service life and small in loss, and the speed regulation accuracy of the speed regulation device can be higher by adopting the magnetic suspension technology.

Description

Technical Field

[0001] The invention relates to the field of permanent magnet speed regulation systems, and in particular to a magnetic suspension permanent magnet speed regulator for a cylindrical linear motor and a speed regulation method. Background Art

[0002] With the continuous development of magnetic levitation technology and permanent magnet speed regulator technology, magnetic levitation permanent magnet speed regulator technology is also constantly breaking through and innovating. It combines the friction reduction and suspension characteristics of magnetic levitation technology with the efficient speed regulation advantages of permanent magnet speed regulators to achieve more efficient and energy-saving motor speed regulation. At present, researchers are working to improve the speed regulation range, efficiency, stability and reliability of magnetic levitation permanent magnet speed regulators. In addition, by introducing intelligent control technology, the automatic and intelligent control of magnetic levitation permanent magnet speed regulators can be realized, so that they can achieve the optimal speed regulation effect under various working conditions.

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

[0004] The invention discloses a magnetic suspension permanent magnet speed regulator for a cylindrical linear motor and a speed regulation method, which can make the structure simpler, eliminate friction loss, prolong the service life of the motor, reduce loss, and simultaneously adopt magnetic suspension technology to make the speed regulation more accurate. Summary of the invention

[0005] Purpose of the invention: In view of the problems pointed out in the background technology, the present invention proposes a cylindrical linear motor magnetic suspension permanent magnet speed regulator and speed regulation method, which can solve the problem that the existing motors generate a lot of losses and low efficiency due to the mutual contact between their structures.

[0006] Technical solution: The present invention provides a cylindrical linear motor magnetic suspension permanent magnet speed regulator, 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 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 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 winding and permanent magnet are bonded to the primary stator and the metal plate respectively; the secondary mover composed of the permanent magnet and the metal plate is fixed on the non-magnetic conductive 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 conductive 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] Furthermore, the cylinder-type permanent magnet speed regulator includes an outer cylinder and an inner cylinder; the left side of the outer cylinder is connected to the rotating shaft, and a conductor ring is fixed on the right side of the inner cavity of the outer cylinder; the right side of the inner cylinder is connected to the load shaft, and a permanent magnet ring is fixed on the left outer wall of the inner cylinder, and the conductor ring is directly opposite to the permanent magnet ring.

[0011] Furthermore, the inner cylindrical body of the drum-type permanent magnet speed regulator is connected to the load shaft through a ball bearing passing through the end cover.

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

[0013] Step (1): When the cylindrical linear motor detects a change in load information, a three-phase alternating current is supplied to the three-phase winding of the cylindrical linear motor, thereby forming a traveling wave magnetic field around the primary stator, and the permanent magnet on the secondary mover generates a permanent magnetic field;

[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, generating a thrust that pushes the secondary mover to move axially along the non-magnetic conductive plate;

[0015] Steps: 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 center position and is offset;

[0016] Step (3): Detect the axial displacement of the rotating shaft through the displacement detection ring, and feed it back to the radial-axial three-degree-of-freedom hybrid magnetic bearing, adjust the current of the winding B of the radial-axial three-degree-of-freedom hybrid magnetic bearing, generate corresponding axial suction force, drive the rotating shaft to move axially, and return the rotor B to the center position; wherein the winding B includes a radial suspension winding and an axial suspension winding, the radial suspension winding and the radial two-degree-of-freedom radial magnetic bearing control the radial suspension of the rotating shaft, and the axial suspension winding controls the rotor B to follow the axial movement of the secondary mover;

[0017] Step (4): The drum-type 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 center position of the radial-axial three-degree-of-freedom hybrid magnetic bearing.

[0018] Furthermore, the maximum axial displacement of the barrel-type 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 secondary mover movement is less than 0.5 mm of the axial air gap of the radial-axial three-degree-of-freedom hybrid magnetic bearing, the shaft follow-up is adjusted in real time.

[0019] Furthermore, when the magnetic field meshing area between the conductor ring and the permanent magnet ring increases, the transmitted torque increases and the speed of the load increases; when the magnetic field meshing area between the conductor ring and the permanent magnet ring decreases, the transmitted torque decreases and the speed of the load decreases.

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

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

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

[0023] S 轴 is the magnetic pole area of ​​the axial stator of the radial-axial three-degree-of-freedom hybrid magnetic bearing, then Determine the maximum axial suspension force F 轴 , μ0 is the vacuum permeability, μ0=4π×10 -7 H / m.

[0024] Beneficial effects:

[0025] The present invention forms a magnetic levitation permanent magnet speed regulator by combining a hybrid magnetic bearing with a motor drive, thereby reducing friction between structures, lowering losses, and increasing power. Moreover, since there is no friction, the speed range of the modulation is larger. Meanwhile, compared with the traditional permanent magnet speed regulator, the precision is also improved due to the use of more sophisticated magnetic levitation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure 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-cylindrical permanent magnet speed regulator, 22-outer cylinder, 23-inner cylinder, 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. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0029] Figure 1 The structure diagram of a cylindrical linear motor magnetic suspension permanent magnet speed regulator of the present invention 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 cylindrical permanent magnet speed regulator 21, a housing 28 and an end cover 27.

[0030] 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. The left and right displacement detection devices 6 and 18 are placed on both sides of the two hybrid magnetic bearings, respectively.

[0031] The cylindrical 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 radial two-degree-of-freedom hybrid magnetic bearing 10 on the left and the axial stator 17 of the radial-axial three-degree-of-freedom hybrid magnetic bearing on the right are both fixed on the non-magnetic conductive plate 29, the rotor A13 of the radial two-degree-of-freedom hybrid magnetic bearing 10 and the rotor B15 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 are both fixed on the rotating shaft 26, the winding A12 of the radial two-degree-of-freedom hybrid magnetic bearing 10 is wound on the radial stator 11, and the winding B16 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 is wound on the axial stator 17.

[0034] The left and right displacement detection devices 6 and 18 are used to detect the displacement of the rotating shaft 26 and the rotor of the hybrid magnetic bearing. 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 are directly opposite to the displacement detection ring 9 and are used to detect radial and axial displacement deviations, respectively.

[0035] The drum-type permanent magnet speed regulator 21 includes an outer cylinder 22 and an inner cylinder 23. The left side of the outer cylinder 22 is connected to the rotating shaft 26. A conductor ring 30 is fixed to the right side of the inner cavity of the outer cylinder 22. The right side of the inner cylinder 23 is connected to the load shaft 25. The inner cylinder 23 is connected to the load shaft 25 through the end cover 27 via a ball bearing 24. A permanent magnet ring 31 is fixed to the left side of the inner cylinder 23, and the conductor ring 30 and the permanent magnet ring 31 are directly opposite.

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

[0037] Step (1): When the cylindrical linear motor 1 detects a change in load information, it starts to adjust the speed. When three-phase alternating current is passed into the three-phase winding 2 of the cylindrical linear motor 1, a traveling wave magnetic field is formed around the primary stator 5, and the permanent magnet of the secondary mover generates 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, generating a thrust that pushes the secondary mover to move axially along the non-magnetic conductive plate 29 below it;

[0039] Step (3): The secondary mover moves axially under the action of 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 also move axially, 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 center position and is offset.

[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, the winding B16 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 needs to be current-regulated to generate a corresponding axial thrust, drive the shaft to move axially, and return the rotor B15 to the center position. The axial displacement of the shaft 26 is detected by the displacement detection ring and fed back to the radial-axial three-degree-of-freedom hybrid magnetic bearing 14, and the winding B16 of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 is current-regulated to generate a corresponding axial suction force, drive the shaft 26 to move axially, and return the rotor B15 to the center position; wherein the winding B16 includes a radial suspension winding and an axial suspension winding, the radial suspension winding and the radial two-degree-of-freedom radial magnetic bearing 10 control the shaft 26 to suspend radially, and the axial suspension winding controls the rotor B15 to follow the secondary mover axially.

[0041] Step (5): The cylinder-type permanent magnet speed regulator 21 adjusts the magnetic field meshing area between the conductor ring 30 on the outer cylinder 22 and the permanent magnet ring 31 on the inner cylinder 23 according to the feedback amount, so that the rotor B15 is always at 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 load speed 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 load speed becomes lower.

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

[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 With load force F 负 The relationship between them is determined as follows:

[0044] Select the permanent magnetic material of the radial-axial three-degree-of-freedom hybrid magnetic bearing 14 and 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 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 μ0 is the vacuum magnetic permeability, μ0=4π×10 -7 H / m.

[0045] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot 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 included in 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 two displacement detection rings are respectively placed on both sides; 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), a traveling wave magnetic field is formed around the primary stator (5), and a 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 radial 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 ; According to 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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