A Rotating Lorentz Force Magnetic Bearing

Abstract

The invention discloses a rotating Lorentz force magnetic bearing, which is mainly composed of four parts: an inner stator component, an outer stator component, a rotor component and a servo component. The inner stator component mainly includes: an inner upper magnetic steel, an inner lower magnetic steel and an inner magnetic conductive ring; the outer stator component mainly includes: an outer upper magnetic steel, an outer lower magnetic steel and an outer magnetic conductive ring; the rotor component mainly includes: a winding bracket and a rectangular closed-loop winding group; the servo component mainly includes: an angular displacement sensor, a current controller and a stator and rotor bearing member; the inner and outer stators adopt double-ring-shaped, co-rotating radially magnetized magnetic steels to create a high uniformity magnetic field, which greatly improves the magnetic density linearity; the rectangular closed-loop winding group is used to cut the magnetic lines of force to generate a force couple, and the stator and rotor of the magnetic bearing are driven to perform relatively large-angle, high-precision, and high-dynamic reciprocating rotational motion, thereby overcoming the disadvantage of small deflection angle of traditional deflection Lorentz force magnetic bearings and greatly expanding the application range of Lorentz force magnetic bearings.

Description

Technical Field

[0001] The present invention relates to a non-contact magnetic suspension bearing, and particularly to a rotating Lorentz force magnetic bearing. Technical Background

[0002] Magnetic bearing technology has been widely used in the fields of aerospace, industrial control, etc. due to its advantages such as high rotational speed, active control, frictionless, long service life, adjustable stiffness and damping. From the perspective of the generation of electromagnetic force, magnetic bearings can be divided into reluctance magnetic bearings and Lorentz force magnetic bearings. The reluctance magnetic bearing generates a magnetic field through the current in the coil, and then generates a suction force, and the electromagnetic force is in a square relationship with the current. The generation of electromagnetic force in the Lorentz force magnetic bearing is based on Ampere's law, that is, an Ampere force is generated when a current-carrying coil is in a magnetic field. After the Lorentz force magnetic bearing scheme is set, the electromagnetic force generated by the current-carrying coil is only related to the current, and is theoretically in a linear relationship, with good linearity, high control accuracy, and good dynamic performance. Therefore, the Lorentz force magnetic bearing is suitable for high-precision control and can be used as a drive mechanism for high-dynamic agile maneuvering of a space-based platform, improving the maneuvering efficiency and flexibility of the platform.

[0003] In the prior art, a double permanent magnet deflection Lorentz force magnetic bearing described in the Chinese patent with the application number 201610597382.X has a cylindrical cup-shaped stator, and the magnetic gap is in the shape of a cylindrical shell, and the deflection angle of the Lorentz force magnetic bearing is very small. A two-degree-of-freedom Lorentz force outer-rotor spherical magnetic bearing described in the Chinese patent with the application number 201510243920.0 uses a spherical shell-shaped air gap to overcome the disadvantage of the small deflection angle of the existing cylindrical air gap Lorentz force magnetic bearing, but this scheme uses a single-loop steel structure, with a low air-gap magnetic density, large suspension power consumption, and coupling between the two degrees of freedom of deflection. A two-degree-of-freedom Halbach array explicit Lorentz force deflection magnetic bearing described in the Chinese patent with the application number 201610920731.7 uses a Halbach array magnetic steel structure scheme to increase the air-gap magnetic field strength and increase the deflection torque, but since the magnetic steel is located at the magnetic pole ends, obvious magnetic leakage occurs at the air-gap edge, reducing the magnetic density uniformity. Summary of the Invention

[0004] The object of the present invention is to provide a rotating Lorentz force magnetic bearing with high magnetic density uniformity, high output torque accuracy, and large deflection angle.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] The rotating Lorentz force magnetic bearing of the present invention mainly consists of four parts: an inner stator assembly, an outer stator assembly, a rotor assembly, and a servo assembly. The inner stator assembly mainly includes: an inner upper radially magnetized magnet (3A), an inner lower radially magnetized magnet (3B), and an inner magnetic conducting ring (5); the outer stator assembly mainly includes: an outer upper radially magnetized magnet (4A), an outer lower radially magnetized magnet (4B), and an outer magnetic conducting ring (6); the rotor assembly mainly includes: a winding support (1), a rectangular closed-loop winding (2); the servo assembly (7) mainly includes: an angular displacement sensor, a current controller, and a stator-rotor carrier; the inner upper radially magnetized magnet (3A), the inner lower radially magnetized magnet (3B), the outer upper radially magnetized magnet (4A), and the outer lower radially magnetized magnet (4B) have the same magnetization direction; the outer magnetic conducting ring (6) is located radially outside the outer stator assembly, the outer upper radially magnetized magnet (4A) is located at the upper end of the inner side of the outer magnetic conducting ring (6) in the radial direction, the outer lower radially magnetized magnet (4B) is located at the lower end of the inner side of the outer magnetic conducting ring (6) in the radial direction, and the outer magnetic conducting ring (6) is concentric with the outer upper radially magnetized magnet (4A) and the outer lower radially magnetized magnet (4B); the inner magnetic conducting ring (5) is located radially inside the inner stator assembly, the inner upper radially magnetized magnet (3A) is located at the upper end of the outer side of the inner magnetic conducting ring (5) in the radial direction, the inner lower radially magnetized magnet (3B) is located at the lower end of the inner side of the inner magnetic conducting ring (5) in the radial direction, and the inner magnetic conducting ring (5) is concentric with the inner upper radially magnetized magnet (3A) and the inner lower radially magnetized magnet (3B); the inner and outer stator assemblies form a closed-loop magnetic flux circuit and form a highly uniform continuous magnetic field at the working air gap between the two; the winding support (1) is located between the air gaps of the inner and outer radially magnetized magnets; the rectangular closed-loop winding (2) is wound and glued to the winding support, and the coil plane is perpendicular to the plane of the inner and outer radially magnetized magnets. After the rectangular winding is energized, the upper and lower side coils of it axially pass through the working air gap and cut the magnetic force lines, generating a linear electromagnetic force; because the directions of the currents of the upper and lower side coils passing through the air gap magnetic field are opposite, a pair of parallel forces with equal magnitude and opposite directions are generated in the upper and lower air gaps respectively, forming a couple. By detecting the angular displacement of the rotor assembly through the servo assembly and adjusting the magnitude and direction of the coil current, the rotor assembly is driven to reciprocate with high precision and high dynamics around the axial 1π space;

[0007] As can be seen from the technical solutions provided by the present invention above, for the rotating Lorentz force magnetic bearing provided by the present invention, an inner and outer double-ring and co-rotating shaft radially magnetized magnet is used to create a highly uniform magnetic field, greatly improving the magnetic density uniformity; the inner and outer concentric magnetic conducting rings and the inner and outer steel rings form a magnetic flux circuit; by rotating and cutting the magnetic force lines through the rectangular closed-loop winding, the stator and rotor of the rotating Lorentz force magnetic bearing are driven to perform reciprocating motion with a large angle, high precision, and high dynamics, overcoming the shortcoming of the small deflection angle of the traditional deflection Lorentz force magnetic bearing. Compared with the magnetic resistance type deflection magnetic bearing, the output torque accuracy is higher. Description of the Drawings

[0008] Figure 1Rotational sectional view of the rotational Lorentz force magnetic bearing of the present invention;

[0009] Figure 2 Magnetic circuit diagram of the present invention;

[0010] Figure 3 Pole sectional view of the present invention. Specific implementation

[0011] The embodiments of the present invention will be further described in detail below. The content not described in detail in the embodiments of the present invention belongs to the prior art well known to those skilled in the art.

[0012] The preferred specific implementation of the rotational Lorentz force magnetic bearing of the present invention is as follows:

[0013] It mainly consists of four parts: an inner stator assembly, an outer stator assembly, a rotor assembly, and a servo assembly, and is characterized in that: The inner stator assembly mainly includes: an inner upper radially magnetized magnet (3A), an inner lower radially magnetized magnet (3B), and an inner magnetic conductive ring (5); The outer stator assembly mainly includes: an outer upper radially magnetized magnet (4A), an outer lower radially magnetized magnet (4B), and an outer magnetic conductive ring (6); The rotor assembly mainly includes: a winding support (1), a rectangular closed-loop winding (2); The servo assembly (7) mainly includes: an angular displacement sensor, a current controller, and a stator-rotor carrier; The inner upper radially magnetized magnet (3A), the inner lower radially magnetized magnet (3B), the outer upper radially magnetized magnet (4A), and the outer lower radially magnetized magnet (4B) have the same magnetization direction; The outer magnetic conductive ring (6) is located radially outside the outer stator assembly, the outer upper radially magnetized magnet (4A) is located at the upper end of the inner side of the outer magnetic conductive ring (6) in the radial direction, the outer lower radially magnetized magnet (4B) is located at the lower end of the inner side of the outer magnetic conductive ring (6) in the radial direction, and the outer magnetic conductive ring (6) is concentric with the outer upper radially magnetized magnet (4A) and the outer lower radially magnetized magnet (4B); The inner magnetic conductive ring (5) is located radially inside the inner stator assembly, the inner upper radially magnetized magnet (3A) is located at the upper end of the outer side of the inner magnetic conductive ring (5) in the radial direction, the inner lower radially magnetized magnet (3B) is located at the lower end of the inner side of the inner magnetic conductive ring (5) in the radial direction, and the inner magnetic conductive ring (5) is concentric with the inner upper radially magnetized magnet (3A) and the inner lower radially magnetized magnet (3B); The inner and outer stator assemblies form a closed-loop magnetic flux circuit and form a highly uniform continuous magnetic field at the working air gap between them; The winding support (1) is located in the air gap between the inner radially magnetized magnet and the outer radially magnetized magnet; The rectangular closed-loop winding (2) is wound and glued to the coil support, and the coil plane is perpendicular to the plane of the inner and outer radially magnetized magnets. After the rectangular winding is energized, the upper and lower side coils of it axially cross the working air gap and cut the magnetic force lines to generate a linear electromagnetic force; Because the directions of the currents of the upper and lower side coils passing through the air gap magnetic field are opposite, a pair of parallel forces with equal magnitude and opposite directions are generated in the upper and lower air gaps respectively, forming a couple. By detecting the angular displacement of the rotor assembly and adjusting the magnitude and direction of the coil current through the servo assembly, the rotor assembly is driven to rotate reciprocally with high precision and high dynamics around the axial 1π space;

[0014] The outer upper radially magnetized magnet, the outer lower radially magnetized magnet, the inner upper radially magnetized magnet, and the inner lower radially magnetized magnet are all made of permanent magnet alloy materials, and their magnetization directions are all: S on the upper side and N on the lower side; The four radially magnetized magnets are all annular magnets and are concentric, and the annular central angles are the same; The radial thickness of the inner magnet ring is greater than the radial thickness of the outer magnet ring.

[0015] The described winding support is in the shape of a thin-shell cylinder, axially perpendicular to the magnetic field between the inner and outer permanent magnets and concentric with the inner and outer permanent magnet rings; the rectangular closed-loop winding is wound from the ground of the thin-shell cylindrical winding support to the cylindrical surface, and the coils wound on the cylindrical surface are perpendicular to the magnetic field formed by the inner and outer permanent magnets, and the coils wound on the bottom surface of the thin shell are parallel to the plane where the inner and outer permanent magnet rings are located, and the bottom circular coils are wound on the cylindrical stator support; the coil support is made of a high-temperature resistant and high-strength composite material.

[0016] The described outer magnetic conductive ring, outer upper radial permanent magnet ring, inner upper radial permanent magnet ring, inner magnetic conductive ring, inner lower radial permanent magnet ring and outer lower radial permanent magnet ring form a magnetic flux circuit; both the inner magnetic conductive ring and the outer magnetic conductive ring are made of soft magnetic conductive materials with high magnetic permeability.

[0017] The described servo assembly includes an angular displacement sensor, a current controller, and a stator-rotor carrier; among them, the angular displacement sensor is an eddy current displacement sensor for real-time high-precision angular position detection of the rotor; the current controller realizes current commutation of the rotor and controls the rotor to deflect to a specific position; the stator-rotor carrier provides mechanical, circuit and electrical support for the outer stator, inner stator and rotor assembly;

[0018] After the coil is energized, the coils between the outer upper radial magnetized permanent magnet and the inner upper radial magnetized permanent magnet and the coils between the outer lower radial magnetized permanent magnet and the inner lower radial magnetized permanent magnet are subjected to a pair of force couples with equal magnitude and opposite directions, forming a torque to control the single-degree-of-freedom deflection of the rotor in the radial direction.

[0019] The principle of the above solution is:

[0020] The rotating Lorentz force magnetic bearing of the present invention is a single-degree-of-freedom radial deflection control magnetic bearing, which can control the single-degree-of-freedom deflection of the rotor in the radial direction. As Figure 2 shown, the radial magnetic circuit of the present invention is: the magnetic flux starts from the S pole of the outer upper radial magnetized permanent magnet, passes through the radial air gap, reaches the upper end of the inner upper radial magnetized permanent magnet, then flows out from the N pole of the inner upper radial magnetized permanent magnet, passes through the inner magnetic conductive ring, then enters from the S pole of the inner lower radial magnetized permanent magnet, passes through the radial air gap, reaches the S pole of the outer lower radial magnetized permanent magnet, and flows out from the N pole of the outer lower radial magnetized permanent magnet, then enters the outer magnetic conductive ring and returns to the S pole of the outer upper radial magnetized permanent magnet to form a closed magnetic circuit; after the rectangular closed-loop winding coil is energized, the coils between the outer upper radial magnetized permanent magnet and the inner upper radial magnetized permanent magnet and the coils between the outer lower radial magnetized permanent magnet and the inner lower radial magnetized permanent magnet are subjected to a pair of force couples with equal magnitude and opposite directions, forming a torque to control the single-degree-of-freedom deflection of the rotor in the radial direction.

[0021] The advantages of the present invention compared with the prior art are:

[0022] The present invention creates a high-uniformity magnetic field by using an inner and outer double-ring, coaxial radial magnetized permanent magnets, greatly improving the magnetic density uniformity; the inner and outer co-centric magnetic conduction rings and the inner and outer steel rings form a magnetic flux circuit. By rotating a rectangular closed-loop winding to cut the magnetic force lines, the rotation Lorentz force magnetic bearing is driven to perform large-angle, high-precision, and high-dynamic reciprocating motion between the stator and the rotor, overcoming the shortcoming of the small deflection angle of the traditional deflection Lorentz force magnetic bearing; compared with the magnetic resistance type deflection magnetic bearing, the output torque accuracy is higher. Specific embodiments:

[0024] As Figure 1 and Figure 3 shown, the rotation Lorentz force magnetic bearing mainly consists of four parts: an inner stator assembly, an outer stator assembly, a rotor assembly, and a servo assembly. It is characterized in that: the inner stator assembly mainly includes: an inner upper radially magnetized permanent magnet (3A), an inner lower radially magnetized permanent magnet (3B), and an inner magnetic conduction ring (5); the outer stator assembly mainly includes: an outer upper radially magnetized permanent magnet (4A), an outer lower radially magnetized permanent magnet (4B), and an outer magnetic conduction ring (6); the rotor assembly mainly includes: a winding support (1) and a rectangular closed-loop winding (2); the servo assembly (7) mainly includes: an angular displacement sensor, a current controller, and a stator-rotor bearing member; the inner upper radially magnetized permanent magnet (3A), the inner lower radially magnetized permanent magnet (3B), the outer upper radially magnetized permanent magnet (4A), and the outer lower radially magnetized permanent magnet (4B) have the same magnetization direction; the outer magnetic conduction ring (6) is located radially outside the outer stator assembly, the outer upper radially magnetized permanent magnet (4A) is located at the upper end of the inner side of the outer magnetic conduction ring (6) in the radial direction, the outer lower radially magnetized permanent magnet (4B) is located at the lower end of the inner side of the outer magnetic conduction ring (6) in the radial direction, and the outer magnetic conduction ring (6) is co-centric with the outer upper radially magnetized permanent magnet (4A) and the outer lower radially magnetized permanent magnet (4B); the inner magnetic conduction ring (5) is located radially inside the inner stator assembly, the inner upper radially magnetized permanent magnet (3A) is located at the upper end of the outer side of the inner magnetic conduction ring (5) in the radial direction, the inner lower radially magnetized permanent magnet (3B) is located at the lower end of the inner side of the inner magnetic conduction ring (5) in the radial direction, and the inner magnetic conduction ring (5) is co-centric with the inner upper radially magnetized permanent magnet (3A) and the inner lower radially magnetized permanent magnet (3B); the inner and outer stator assemblies form a closed-loop magnetic flux circuit and form a high-uniformity continuous magnetic field at the working air gap between them; the winding support (1) is located between the air gaps of the inner radially magnetized permanent magnet and the outer radially magnetized permanent magnet; the rectangular closed-loop winding (2) is wound and glued to the winding support, and the coil plane is perpendicular to the plane of the inner and outer radially magnetized permanent magnets. After the rectangular winding is energized, the upper and lower side coils of it pass through the working air gap axially and cut the magnetic force lines, generating a linear electromagnetic force; because the directions of the currents of the upper and lower side coils passing through the air gap magnetic field are opposite, a pair of parallel forces with equal magnitude and opposite directions are generated in the upper and lower air gaps respectively, forming a couple. By detecting the angular displacement of the rotor assembly by the servo assembly and adjusting the magnitude and direction of the coil current, the rotor assembly is driven to rotate reciprocally with high precision and high dynamics around the axial 1π space;

[0025] Figure 2This is the magnetic circuit diagram of the present invention. The magnetic circuit of the present invention is as follows: The magnetic flux starts from the S pole of the outer upper radially magnetized magnet (4A), passes through the radial air gap, reaches the upper end of the inner upper radially magnetized magnet (3A), then flows out from the N pole of the inner upper radially magnetized magnet (3A), passes through the inner magnetic conduction ring (5), then enters from the S pole of the inner lower radially magnetized magnet (3B), passes through the radial air gap, reaches the S pole of the outer lower radially magnetized magnet (4B), and flows out from the N pole of the outer lower radially magnetized magnet (4B), then enters the outer magnetic conduction ring (6), and returns to the S pole of the outer upper radially magnetized magnet (4A) to form a closed magnetic circuit.

[0026] As mentioned above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A rotating Lorentz force magnetic bearing, characterized in that: The invention mainly consists of four parts: an inner stator component, an outer stator component, a rotor component and a servo component. The inner stator component mainly comprises: an inner upper radial magnetized magnetic steel (3A), an inner lower radial magnetized magnetic steel (3B), and an inner magnetic guide ring (5); the outer stator component mainly comprises: an outer upper radial magnetized magnetic steel (4A), an outer lower radial magnetized magnetic steel (4B), and an outer magnetic guide ring (6); the rotor component mainly comprises: a winding support (1), a rectangular closed winding (2); the servo component (7) mainly comprises: an angular displacement sensor, a current controller, a stator and rotor bearing The magnetizing directions of the inner upper radial magnetizing magnetic steel (3A), the inner lower radial magnetizing magnetic steel (3B), the outer upper radial magnetizing magnetic steel (4A), and the outer lower radial magnetizing magnetic steel (4B) are the same; the outer magnetic ring (6) is located radially outside the outer stator component, the outer upper radial magnetizing magnetic steel (4A) is located at the radial inner upper end of the outer magnetic ring (6), and the outer lower radial magnetizing magnetic steel (4B) is located at the radial inner lower end of the outer magnetic ring (6); the outer magnetic ring (6) is co-centered with the outer upper radial magnetizing magnetic steel (4A) and the outer lower radial magnetizing magnetic steel (4B); the inner magnetic ring ( 5) is located radially inside the inner stator component, the inner upper radial magnetizing magnetic steel (3A) is located at the radial outer upper end of the inner magnetic ring (5), the inner lower radial magnetizing magnetic steel (3B) is located at the radial inner lower end of the inner magnetic ring (5), and the inner magnetic ring (5) and the inner upper radial magnetizing magnetic steel (3A) and the inner lower radial magnetizing magnetic steel (3B) are co-centered; the inner and outer stator components form a closed-loop magnetic flux circuit, and a highly uniform continuous magnetic field is formed at the working air gap between the two; the winding bracket (1) is located between the air gaps of the inner radial magnetizing magnetic steel and the outer radial magnetizing magnetic steel; the inner magnetic ring (5) and the outer magnetic ring (3A) are co-centered; the inner and outer stator components form a closed-loop magnetic flux circuit, and a highly uniform continuous magnetic field is formed at the working air gap between the two; the winding bracket (1) is located between the air gaps of the inner radial magnetizing magnetic steel and the outer radial magnetizing magnetic steel; the inner magnetic ring (5) and the outer magnetic ring (3B) are co-centered; the inner magnetic ring (5) and the outer magnetic ring (3A) are co-centered; the inner and outer stator components form a closed-loop magnetic flux circuit, and a highly uniform continuous magnetic field is formed at the working air gap between the inner and outer radial magnetizing magnetic steel ... inner magnetic ring (5) and the outer magnetic ring (3B) are co-centered; the inner magnetic ring (5) and the outer magnetic ring (3A) are co-centered; the inner magnetic ring (5) and the outer magnetic ring (3B The rectangular winding group (2) is wound around and glued to the winding bracket, and the coil plane is perpendicular to the inner and outer radial magnetized magnetic steel planes. After the rectangular winding is energized, the upper and lower coils thereof axially pass through the working air gap and cut the magnetic lines of force, thereby generating a linear electromagnetic force. Since the directions of the currents of the upper and lower coils passing through the air gap magnetic field are opposite, a pair of parallel forces of equal magnitude and opposite direction are generated in the upper and lower air gaps respectively, forming a force couple. The servo component detects the angular displacement of the rotor component, adjusts the magnitude and direction of the coil current, and drives the rotor component to reciprocate around the axial 1π space with high precision and high dynamics.

2. A rotary Lorentz force magnetic bearing according to claim 1, characterized in that: The outer upper radial magnetized magnetic steel (4A), the outer lower radial magnetized magnetic steel (4B), the inner upper radial magnetized magnetic steel (3A), and the inner lower radial magnetized magnetic steel (3B) are all made of permanent magnet alloy materials, and their magnetization directions are all: upper S and lower N; the four radial magnetized magnetic steels are all annular magnetic steels, and have a common center and the same annular center angle; the radial thickness of the inner magnetic steel ring is greater than the radial thickness of the outer magnetic steel ring.

3. The rotary Lorentz force magnetic bearing according to claim 1, characterized in that: The winding support (1) is a thin-shell cylindrical coil support, which is installed axially perpendicular to the magnetic field between the inner and outer magnetic steels and is co-centric with the inner and outer magnetic steel rings; the rectangular closed winding coil (2) is wound from the bottom surface of the thin-shell cylindrical coil support to the surface of the cylinder, the coil wound on the cylinder is perpendicular to the magnetic field formed by the inner and outer magnetic steels, the coil wound on the bottom surface of the thin shell is parallel to the plane where the inner and outer magnetic steel rings are located, and the bottom circular coil is wound on the cylindrical stator support; the coil support is a high-temperature resistant and high-strength composite material.

4. The rotary Lorentz force magnetic bearing according to claim 1, characterized in that: The outer magnetic conductive ring (6), the outer upper radial magnetic steel ring (4A), the inner upper radial magnetic steel ring (3A), the inner magnetic conductive ring (5), the inner lower radial magnetic steel ring (3B) and the outer lower radial magnetic steel ring (4B) form a magnetic flux circuit; the inner magnetic conductive ring (5) and the outer magnetic conductive ring (6) are both made of soft magnetic conductive materials with strong magnetic permeability.

5. The rotary Lorentz force magnetic bearing according to claim 1, characterized in that: The servo assembly (7) comprises an angular displacement sensor, a current controller and a stator-rotor bearing member; wherein the angular displacement sensor is an eddy current displacement sensor, which performs real-time high-precision angular position detection on the rotor; the current controller realizes current commutation of the rotor and controls the rotor to deflect to a specific position; the stator-rotor bearing member provides mechanical, circuit and electrical support for the outer stator, inner stator and rotor assembly.

6. The rotary Lorentz force magnetic bearing according to claim 1, characterized in that: When the coil is energized, the coil (2) located between the outer upper radial magnetized magnetic steel (4A) and the inner upper radial magnetized magnetic steel (3A) and the coil (2) located between the outer lower radial magnetized magnetic steel (4B) and the inner lower radial magnetized magnetic steel (3B) are subjected to a pair of parallel forces of equal magnitude and opposite directions, forming a torque to control the single degree of freedom deflection of the rotor around the radial direction.

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