RU2819728C1 - Combined superconducting magnetic bearing - Google Patents

Abstract

FIELD: elements of electrical equipment.

SUBSTANCE: use for electrical devices. Essence of the invention consists in the fact that the combined superconducting magnetic bearing consists of a stator in the form of a hollow tube made of a non-magnetic material with high heat conductivity, on the outer side of which superconducting windings are made, each of which is an HTS tape wound in layers, cooling system of HTS tapes and rotor made of non-magnetic material, on which permanent magnets are located in slots, wherein geometrical centres of every winding of HTS tapes and every row of rotor magnets are located opposite each other. Besides, rotor and stator axes of symmetry coincide. On one of the stator edges on its outer surface around the pipe there are stacks of HTS tapes, consisting of 1–100 layers, wherein the stacks of HTS tapes are overlapped to form a hollow superconducting prism with a wall thickness of 12 mm, at the base of which lies a regular polygon, wherein the number of sides of the polygon is determined by the diameter of the above pipe, further from the hollow superconducting prism at a distance of up to 20 mm on the outer surface of the above pipe are installed one after another along the vertical axis of pipe 5+4 n, where n=0, 1.2n, windings of HTS tapes with width of 12 mm, wherein each winding of HTS tapes consists of 1 to 70 layers and is coated with a layer of heat-insulating material, around the stator opposite to the HTS tapes windings at a distance of not more than 30 mm from the winding upper layer there is a cylindrical rotor made of non-magnetic material, on the inner side of which 5+4 n are fixed, where n=0, 1, 2…n, rows of permanent magnets with dimensions of 10×10×10 mm, in addition, rows of magnets are located at distance of 2 mm from each other in vertical direction with formation of Halbach magnetic assembly, wherein geometrical centres of each winding of HTS tapes and each row of magnets are located opposite each other and in each row all magnets are oriented in one direction.

EFFECT: increase of constant magnetic field and improvement of device stabilization at external actions, which tend to cause relative translational displacement of rotor and stator.

1 cl, 3 dwg

Description

The invention relates to the field of non-contact magnetic bearings using high-temperature superconducting (HTSC) tapes and can be used in the design of electrical devices for various purposes with a massive rotating rotor/shaft.

A known superconducting magnetic bearing (RU 174146 U1, Federal State Budgetary Educational Institution of Higher Education "National Research University "MPEI", 10/04/2017), which includes in its design a supporting pipe of a cryostat, on the inner and outer surfaces of which cylindrical HTSC elements are fixed, as well as internal and external rotors with installed on them with ring magnets of alternating polarity. The magnets are magnetized in the axial direction and are separated by inserts made of soft magnetic material. The HTSC elements are cooled by pumping liquid nitrogen through a channel in the cryostat tube. The device operates in a vacuum and therefore does not require additional thermal insulation of the HTSC elements. allows you to reduce the gap between the rotor and stator. The disadvantages of this device include the fact that the device can only operate in a vacuum, which complicates its design and use, as well as insufficient stabilization of the device under external influences.

The closest in technical essence and accepted as a prototype is a superconducting magnetic bearing (RU 197418 U1 Igor Anatolyevich Rudnev, 04/23/2020), which includes a stator containing superconducting elements, a cooling system for HTSC elements and a rotor with magnets placed in it. The stator is a tube made of non-magnetic material with high thermal conductivity, on the outer side of which there are superconducting windings. Cooling of HTSC elements is carried out by cooling the stator tube. The disadvantages of this device include an insufficient constant magnetic field from the permanent magnets of the rotor, leading to poor stabilization of the device under external influences tending to cause a relative translational displacement of the rotor and stator.

The technical result of the invention is to increase the constant magnetic field and improve the stabilization of the device under external influences tending to cause a relative translational displacement of the rotor and stator.

The technical result is achieved by the fact that a combined superconducting magnetic bearing is proposed, consisting of a stator in the form of a hollow tube made of a non-magnetic material with high thermal conductivity, on the outer side of which superconducting windings are made, each of which is a HTSC tape wound in layers, HTSC cooling systems - tapes and a rotor made of non-magnetic material, on which permanent magnets are located in the grooves, forming rows, the number of which coincides with the number of HTSC stator windings, and the geometric centers of each winding of HTSC stator tapes and each row of rotor magnets are located opposite each other, In addition, the symmetry axes of the rotor and stator coincide. On one of the edges of the stator on its outer surface around the pipe there are stacks of HTSC tapes, consisting of 1-100 layers, and stacks of HTSC tapes are installed overlapping to form a hollow superconducting prism with a wall thickness of 12 mm, at the base of which lies a regular polygon, and the number of sides of the polygon is determined by the diameter of the above-mentioned pipe, then from the hollow superconducting prism at a distance of up to 20 mm on the outer surface of the above-mentioned pipe, 5+4 n are installed one after another along the vertical axis of the pipe, where n = 0, 1.2...n, HTSC windings tapes 12 mm wide, each winding of HTSC tapes consists of 1 to 70 layers and is covered with a layer of heat-insulating material; around the stator opposite the windings of HTSC tapes at a distance of no more than 30 mm from the top layer of winding there is a cylindrical rotor made of non-magnetic material on the inside of which 5+4 n, where n=0, 1.2…n, rows of permanent magnets with dimensions of 10×10×10 mm are fixed in the grooves, in addition, the rows of magnets are located at a distance of 2 mm from each other in the vertical direction to form a magnetic Halbach assemblies, with the geometric centers of each winding of HTSC tapes and each row of magnets located opposite each other and in each row all magnets are oriented in the same direction.

Placement on one of the edges of the stator on its outer surface of stacks of HTSC tapes, forming a hollow superconducting prism with a wall thickness of 12 mm, at the base of which lies a regular polygon, and the number of sides of the polygon is determined by the diameter of the above-mentioned pipe, and location at a distance of up to 20 mm from a hollow superconducting prism on the outer surface of the above-mentioned pipe, following each other along the vertical axis of the pipe 5 + 4 n, where n = 0, 1, 2...n, windings of 12 mm wide HTSC tapes, as well as placement on the inner surface of a cylindrical rotor made of non-magnetic material 5+4 n, where n=0, 1, 2…n, rows of permanent magnets to form a Halbach magnetic assembly with dimensions 10×10×10 mm, and the geometric centers of each winding of HTSC tapes and each row of magnets are located opposite each other , leads to stabilization of the bearing structure and prevents its displacement both along the axis of symmetry and across.

When a stack of HTSC tapes consisting of less than 1 layer does not create a superconducting structure, the use of stacks of HTSC tapes consisting of more than 100 layers is not advisable due to the weak increase in the levitation force.

When winding HTSC tapes on the surface of the above-mentioned pipe with less than 1 layer, a superconducting structure does not arise; when winding HTSC tapes with more than 70 layers, cooling of HTSC tapes due to the mechanism of thermal conduction through a solid body is difficult.

The use of rows of permanent magnets forming a Halbach magnetic assembly makes it possible to increase the magnetic field in the area where HTSC tape windings are placed, which in turn leads to stabilization of the bearing structure. To form a Halbach assembly, it is necessary to use a minimum of 5 rows of magnets; the use in the present device of 5+4 n, where n=0, 1, 2...n, rows of permanent magnets allows the formation of a Halbach assembly, in which the fifth row of magnets is the last row of the previous assembly.

When windings of HTSC tapes are placed from a hollow superconducting prism at a distance of more than 20 mm, the magnitude of the magnetic field from the Halbach assembly tends to zero in the direction along the symmetry axis.

When the rotor is placed at a distance of more than 30 mm from the windings of HTSC tapes, the magnitude of the magnetic field from the Halbach assembly tends to zero in the direction perpendicular to the axis of symmetry of the device.

Thus, all the features listed in the summary section of the invention are essential, since they affect the possibility of solving the specified technical problem and make it possible to provide a technical result, since they are in a cause-and-effect relationship with the specified result.

In FIG. 1-3 shows an example of a specific implementation of the device.

In FIG. 1A shows the proposed device assembly: 1 - stator, 2 - stacks of HTSC tapes, 3 - hollow superconducting prism, 4 - windings of HTSC tapes, 5 - cylindrical rotor, 6 - rows of permanent magnets forming a Halbach magnetic assembly.

In FIG. Figure 1B shows a hollow superconducting prism at the base of which lies a regular hexagon: 2 - stacks of HTSC tapes, 3 - hollow superconducting prism.

In FIG. 1B shows a cross-section of the proposed device: 1 - stator, 3 - hollow superconducting prism, 4 - windings of HTSC tapes, 5 - cylindrical rotor, 6 - rows of permanent magnets forming a Halbach magnetic assembly.

Figure 2 shows a graph of the dependence of the restoring force on the magnitude of the vertical displacement.

Figure 3 shows a graph of the dependence of the restoring force on the displacement value in the direction perpendicular to the axis of symmetry.

The device works as follows.

The device contains a stator 1 made of a copper hollow pipe with a diameter of 40 mm. On one of the edges of the stator 1, on its outer surface around the pipe, there are stacks of HTSC tapes 2, consisting of 35 layers, and stacks of HTSC tapes 2 are installed overlapping to form a hollow superconducting prism 3 with a wall thickness of 12 mm, at the base of which lies a regular hexagon , then at a distance of 6 mm from the hollow superconducting prism 3 on the outer surface of the above-mentioned pipe, 5 windings of HTSC tapes 4 with a width of 12 mm are installed one after another along the vertical axis of the pipe, each winding of HTSC tapes 4 consisting of 8 layers and covered with a layer of heat-insulating material , around the stator 1 opposite the windings of HTSC tapes 4 at a distance of 4 mm from the top layer of the winding there is a cylindrical rotor 5 made of ABS plastic, on the inner side of which 5 rows of permanent NdFeB magnets of grade N42 6 with dimensions 10 × 10 are fixed in grooves ×10 mm, in addition, the rows of magnets 6 are located at a distance of 2 mm from each other in the vertical direction to form a Halbach magnetic assembly, and the geometric centers of each winding of HTSC tapes 4 and each row of magnets 6 are located opposite each other and in each row all magnets oriented in one direction.

The proposed device is put into working position: the cylindrical tube of the stator 1 is placed inside the rotor 5 coaxially with it, so that the geometric centers of each winding of HTSC tapes 4 of the stator and each row of magnets 6 of the rotor are located opposite each other. The device is cooled using liquid nitrogen, which is poured inside the stator tube 1. After cooling, the rotor 5 begins to be held outside the stator 1 due to the electromagnetic interaction of the stator windings 4 and stacks 2 with the permanent magnets 6 of the rotor, and can rotate freely relative to the axis of symmetry of the device.

When a vertical (along the axis of symmetry) displacement force is applied to the bearing, a restoring force arises, preventing the relative displacement of the stator and rotor. In FIG. Figure 2 shows a graph of the dependence of the restoring force on the magnitude of the vertical displacement. When a force is applied to the bearing perpendicular to the axis of symmetry, a restoring force is also generated, shown in Fig. 3. Fig. 2 and Fig. 3 confirm the high stability of the proposed design.

Thus, the design of this device makes it possible to increase the magnitude of the constant magnetic field and improve the stabilization of the device under external influences that tend to cause a relative translational displacement of the rotor and stator.

Claims (1)

A combined superconducting magnetic bearing consisting of a stator in the form of a hollow tube made of a non-magnetic material with high thermal conductivity, on the outer side of which there are superconducting windings, each of which is a HTSC tape wound in layers, a cooling system for HTSC tapes and a rotor made of non-magnetic material on which permanent magnets are located in the grooves, forming rows, the number of which coincides with the number of HTSC stator windings, and the geometric centers of each winding of HTSC stator tapes and each row of rotor magnets are located opposite each other, in addition, the symmetry axes of the rotor and stator coincide, characterized in that on one of the edges of the stator on its outer surface around the pipe there are stacks of HTSC tapes, consisting of 1-100 layers, and stacks of HTSC tapes are installed overlapping to form a hollow superconducting prism with a wall thickness of 12 mm, at the base which lies a regular polygon, and the number of sides of the polygon is determined by the diameter of the above-mentioned pipe, then from the hollow superconducting prism at a distance of up to 20 mm on the outer surface of the above-mentioned pipe, 5 + 4 n are installed one after another along the vertical axis of the pipe, where n = 0, 1,2 ...n, windings of HTSC tapes 12 mm wide, each winding of HTSC tapes consists of 1 to 70 layers and is covered with a layer of heat-insulating material; a cylindrical rotor is located around the stator opposite the windings of HTSC tapes at a distance of no more than 30 mm from the top layer of winding made of non-magnetic material, on the inner side of which 5+4 n, where n = 0, 1.2...n, rows of permanent magnets with dimensions of 10 × 10 × 10 mm are fixed in grooves, in addition, rows of magnets are located at a distance of 2 mm from each other from each other in the vertical direction to form a Halbach magnetic assembly, with the geometric centers of each winding of HTSC tapes and each row of magnets located opposite each other and in each row all magnets are oriented in the same direction.