Method, device, system, medium and program product for controlling a magnetic bearing

Abstract

This invention discloses a control method, device, system, storage medium, and computer program product for a magnetic levitation bearing. The method includes: upon receiving a preset levitation command, controlling the operating current of the bearing stator to cause the shaft to move upwards along the inner ring of a backup bearing to a first preset position; if the shaft has reached the first preset position, controlling the operating current of the bearing stator to cause the shaft to move downwards to a second preset position; if the shaft has reached the second preset position, initiating a preset floating shaft program to control the shaft's levitation, thus achieving levitation control of the magnetic levitation bearing. This solution ensures stable levitation of the shaft and reliable levitation of the magnetic levitation bearing by causing the shaft to move upwards along the inner ring of the backup bearing and then downwards until the shaft disengages from the clearance of the backup bearing before executing the floating shaft program.

Description

Technical Field

[0001] This invention belongs to the field of magnetic levitation technology, specifically relating to a control method, device, magnetic levitation bearing system, storage medium, and computer program product for a magnetic levitation bearing, and particularly to a levitation control method, device, magnetic levitation bearing system, storage medium, and computer program product for a magnetic levitation bearing. Background Technology

[0002] The core structure of a magnetic levitation bearing consists of two parts: a bearing rotor and a bearing stator. Its working principle is based on achieving contactless levitation of the rotor using magnetic field force. Magnetic levitation bearings are a new type of high-performance bearing that applies a combination of technologies including rotor dynamics, mechanics, electrical and electronic engineering, control engineering, magnetic materials, testing technology, and digital signal processing. They achieve contactless levitation by separating the bearing rotor and bearing stator using a controlled magnetic field force.

[0003] Magnetic levitation bearings are equipped with a backup bearing, which is used when the bearing shaft is lowered to prevent damage from a direct fall in case of an anomaly. However, when the shaft actually lowers, the backup bearing is pressed down, and due to its clearance, the actual landing point is lower than the ideal landing point. This can cause the shaft to vibrate during the next buoyancy test, making it difficult to maintain stability.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, system, storage medium, and computer program product for a magnetic levitation bearing. This addresses the problem that when the bearing shaft actually lands, the backup bearing is pressed down, and due to the backup bearing's clearance, the actual landing point is lower than the ideal landing point. This causes vibration and instability during subsequent levitation, leading to levitation failure. The invention achieves this by having the bearing move upwards along the inner ring of the backup bearing and then downwards until it breaks free from the backup bearing's clearance, before executing the levitation program. This ensures stable levitation and reliable levitation of the magnetic levitation bearing.

[0006] This invention provides a control method for a magnetic levitation bearing, the magnetic levitation bearing having a rotating shaft, a backup bearing, and a bearing stator; the control method for the magnetic levitation bearing includes: upon receiving a preset levitation command, controlling the operating current of the bearing stator to cause the rotating shaft to move upward along the inner ring of the backup bearing to reach a first preset position; wherein, the preset levitation command is a command used to control the levitation of the magnetic levitation bearing; if it is determined that the rotating shaft moves upward along the inner ring of the backup bearing to reach the first preset position, then controlling the operating current of the bearing stator to cause the rotating shaft to move downward to reach a second preset position; if it is determined that the rotating shaft moves downward to reach the second preset position, then activating a preset floating shaft program to control the rotating shaft to levitate, thereby realizing the levitation control of the magnetic levitation bearing.

[0007] In some embodiments, the method further includes: obtaining the current position of the rotating shaft; determining, based on the current position of the rotating shaft, whether the rotating shaft is satisfied with moving upward along the inner ring of the backup bearing to reach a first preset position; if it is determined that the rotating shaft is not satisfied with moving upward along the inner ring of the backup bearing to reach the first preset position, then returning to continue controlling the operating current of the bearing stator to make the rotating shaft move upward along the inner ring of the backup bearing to reach the first preset position; and / or, determining, based on the current position of the rotating shaft, whether the rotating shaft is satisfied with moving downward to reach a second preset position; if it is determined that the rotating shaft is not satisfied with moving downward to reach the second preset position, then returning to continue controlling the operating current of the bearing stator to make the rotating shaft move downward to reach the second preset position.

[0008] In some embodiments, determining that the rotating shaft travels upward along the inner ring of the backup bearing to reach a first predetermined position includes: determining the position when the rotating shaft travels upward along the inner ring of the backup bearing to reach the top of the inner ring of the backup bearing.

[0009] In some embodiments, the two opposite directions in the horizontal coordinate of the coordinate system where the cross-section of the inner ring of the backup bearing is located are defined as X1 and X2, and the two opposite directions in the vertical coordinate are defined as Y1 and Y2. Determining that the rotating shaft runs upward along the inner ring of the backup bearing to reach a first set position further includes: determining that the rotating shaft runs upward along the inner ring of the backup bearing to reach any position in the plane of symmetry along the Y1Y2 axis.

[0010] In some embodiments, controlling the operating current of the bearing stator to cause the rotating shaft to run downward to a second predetermined position includes: controlling the operating current of the bearing stator to decrease in a preset manner to cause the rotating shaft to run downward to a second predetermined position; wherein, the second predetermined position is the position where the rotating shaft runs upward along the inner ring of the backup bearing to a first predetermined position and then runs downward until the rotating shaft disengages from the clearance of the backup bearing.

[0011] In some embodiments, controlling the operating current of the bearing stator to make the shaft run downward to a second set position further includes: controlling the operating current of the bearing stator to zero so that the shaft runs downward to the second set position by its own weight; wherein, the second set position is the position where the shaft runs upward along the inner ring of the backup bearing to a first set position and then runs downward until the shaft is out of the clearance of the backup bearing.

[0012] In conjunction with the above method, another aspect of the present invention provides a control device for a magnetic levitation bearing, the magnetic levitation bearing having a rotating shaft, a backup bearing, and a bearing stator; the control device for the magnetic levitation bearing includes: a control unit configured to, upon receiving a preset levitation command, control the operating current of the bearing stator to cause the rotating shaft to move upward along the inner ring of the backup bearing to reach a first preset position; wherein, the preset levitation command is a command for controlling the levitation of the magnetic levitation bearing;

[0013] The control unit is further configured to, if it is determined that the rotating shaft runs upward along the inner ring of the backup bearing to reach a first set position, control the operating current of the bearing stator to cause the rotating shaft to run downward to reach a second set position; the control unit is further configured to, if it is determined that the rotating shaft runs downward to reach the second set position, start a preset floating shaft program to control the rotating shaft to levitate, thereby realizing the levitation control of the magnetic levitation bearing.

[0014] In some embodiments, the system further includes: an acquisition unit configured to acquire the current position of the rotating shaft; the control unit further configured to determine, based on the current position of the rotating shaft, whether the rotating shaft is satisfied with moving upward along the inner ring of the backup bearing to reach a first preset position; if it is determined that the rotating shaft is not satisfied with moving upward along the inner ring of the backup bearing to reach the first preset position, then return to continue controlling the operating current of the bearing stator to make the rotating shaft move upward along the inner ring of the backup bearing to reach the first preset position; and / or, the control unit is further configured to determine, based on the current position of the rotating shaft, whether the rotating shaft is satisfied with moving downward to reach a second preset position; if it is determined that the rotating shaft is not satisfied with moving downward to reach the second preset position, then return to continue controlling the operating current of the bearing stator to make the rotating shaft move downward to reach the second preset position.

[0015] In some embodiments, the control unit determines that the rotating shaft runs upward along the inner ring of the backup bearing to reach a first predetermined position, including: determining the position when the rotating shaft runs upward along the inner ring of the backup bearing to reach the top of the inner ring of the backup bearing.

[0016] In some embodiments, the two opposite directions in the horizontal coordinate of the coordinate system where the cross-section of the inner ring of the backup bearing is located are defined as X1 and X2, and the two opposite directions in the vertical coordinate are defined as Y1 and Y2. The control unit determines that the rotating shaft runs upward along the inner ring of the backup bearing to reach a first set position, and further includes: determining that the rotating shaft runs upward along the inner ring of the backup bearing to reach any position in the plane of symmetry along the Y1Y2 axis.

[0017] In some embodiments, the control unit controls the operating current of the bearing stator to cause the rotating shaft to move downward to a second set position, including: controlling the operating current of the bearing stator to decrease in a preset manner to cause the rotating shaft to move downward to a second set position; wherein, the second set position is the position where the rotating shaft moves upward along the inner ring of the backup bearing to a first set position and then moves downward until the rotating shaft disengages from the clearance of the backup bearing.

[0018] In some embodiments, the control unit controls the operating current of the bearing stator to cause the shaft to move downward to a second set position, and further includes: controlling the operating current of the bearing stator to zero so that the shaft moves downward to the second set position by its own weight; wherein, the second set position is the position where the shaft moves upward along the inner ring of the backup bearing to a first set position and then moves downward until the shaft is out of the clearance of the backup bearing.

[0019] In conjunction with the above-mentioned device, the present invention further provides a magnetic levitation bearing system, including: the control device for the magnetic levitation bearing described above.

[0020] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the steps of the control method for the magnetic levitation bearing described above.

[0021] In conjunction with the above method, the present invention further provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the control method for the magnetic levitation bearing described above.

[0022] Therefore, the solution of the present invention, for the levitation control of a magnetic levitation bearing, upon receiving a levitation command, controls the current output by the bearing controller to cause the shaft to move upward along the inner ring of the backup bearing to a first set position (e.g., the shaft reaches the top of the inner ring of the backup bearing, the shaft reaches...). Figure 6 and Figure 7 (e.g., a position in the region between the axes, a position where the shaft reaches the plane of symmetry along the Y1Y2 axis), then reduce the current output of the bearing controller or clear the current output of the bearing controller to execute the action of disengaging from the clearance of the backup bearing, so that the shaft disengages from the clearance of the backup bearing and reaches the set initial position. After the shaft disengages from the clearance of the backup bearing, the floating shaft program of the magnetic levitation bearing is started to make the shaft reach the set position, thereby realizing the lifting and floating control of the magnetic levitation bearing; thus, by making the shaft move upward along the inner ring of the backup bearing and then downward when it is necessary to control the lifting and floating of the magnetic levitation bearing, until the shaft disengages from the clearance of the backup bearing and then the floating shaft program of the magnetic levitation bearing is executed, the shaft is ensured to float stably, so that the magnetic levitation bearing can float reliably.

[0023] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating an embodiment of the control method for magnetic levitation bearings of the present invention;

[0026] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the rotating shaft moves upward to a first predetermined position and / or downward to a second predetermined position;

[0027] Figure 3This is a schematic diagram of a structure of an embodiment of the control device for the magnetic levitation bearing of the present invention;

[0028] Figure 4 Schematic diagram of the shaft lowering of a magnetic levitation bearing Figure 1 ;

[0029] Figure 5 Schematic diagram of the shaft lowering of a magnetic levitation bearing Figure 2 ;

[0030] Figure 6 This is a schematic diagram of the position of the rotating shaft during its motion.

[0031] Figure 7 This is a schematic diagram showing the position of the rotating shaft as it moves to the upper end of the backup bearing.

[0032] Figure 8 This is a schematic diagram illustrating the process of the rotating shaft floating downwards from the top during the levitation of a magnetic levitation bearing.

[0033] Figure 9 This is a schematic diagram showing the levitation of the shaft to a set position during the levitation process of a magnetic levitation bearing.

[0034] Figure 10 This is a flowchart illustrating the buoyancy control method for magnetic levitation bearings.

[0035] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0036] 1-Sensor; 2-Magnetic levitation bearing stator; 3-Outer ring of backup bearing; 4-Ball of backup bearing; 5-Inner ring of backup bearing; 6-Shaft of magnetic levitation bearing; 102-Acquisition unit; 104-Control unit. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] Considering that when the magnetic levitation bearing's shaft actually lands, the backup bearing is pressed down, and due to the backup bearing's clearance, the actual landing point of the shaft is lower than the ideal landing point. This can cause the shaft to vibrate during the next buoyancy attempt, leading to instability and ultimately, failure. Specifically, the industry commonly classifies magnetic levitation bearings into two types: active magnetic levitation bearings and hybrid magnetic levitation bearings. Active magnetic levitation bearings are generally used in larger levitation equipment, with heavier shafts; hybrid magnetic levitation bearings are generally used in relatively smaller levitation equipment. Both types of magnetic levitation bearings require a backup bearing to prevent damage from a direct fall in case of an anomaly. The clearance of the backup bearing is caused by the downward pressure of the shaft.

[0039] Ideally, the shaft should fall onto the backup bearing, such as Figure 4 As shown; however, due to the large self-weight of the active magnetic levitation bearing's shaft, and the superposition of the permanent magnet's magnetic field at the lower end and the shaft's weight in the hybrid magnetic levitation bearing, both exert downward pressure on the backup bearing. Furthermore, the backup bearing has a certain amount of clearance, meaning the actual landing point of the shaft is lower than the ideal landing point, as shown. Figure 5 As shown, if the actual landing point of the shaft is lower than the ideal landing point, the shaft may vibrate during the next buoyancy, making it impossible for the shaft to remain stable.

[0040] Figure 4 Schematic diagram of the shaft lowering of a magnetic levitation bearing Figure 1 , Figure 4 This is used to illustrate that under ideal conditions, if the backup bearing has no clearance, the shaft rests on the inner ring of the backup bearing (e.g., Figure 4 The red ring represents the inner ring, which will not compress downwards. Figure 5 Schematic diagram of the shaft lowering of a magnetic levitation bearing Figure 2 , Figure 5 In practical engineering applications, the shaft rests on the inner ring of the backup bearing. Due to the clearance of the backup bearing, the position where the shaft stops (i.e., Figure 5 The point where the pivot falls in the ring (represented by the solid red line) is lower than... Figure 5 Inner ring dashed line (i.e.) Figure 5 The position of the ring is indicated by the black dashed line in the middle.

[0041] Therefore, the present invention proposes a control method for a magnetic levitation bearing, specifically a levitation control method for a magnetic levitation bearing. This method enables the rotating shaft of the magnetic levitation bearing to complete the levitation process from the upper end of the backup bearing downwards to the levitation position. It allows the rotating shaft to completely disengage from the clearance of the backup bearing before effective control of the magnetic levitation bearing is performed. This ensures that the rotating shaft is stable and does not vibrate during the next levitation process (i.e., the levitation process of the rotating shaft), thus ensuring stable levitation of the magnetic levitation bearing shaft and reducing the failure rate caused by levitation failure.

[0042] According to an embodiment of the present invention, a control method for a magnetic levitation bearing is provided, such as... Figure 1 The diagram shown is a flowchart of an embodiment of the method of the present invention. The magnetic levitation bearing has a rotating shaft, a backup bearing, and a bearing stator, wherein the rotating shaft is as follows: Figure 5 The rotating shaft 6 shown has an inner ring and an outer ring, wherein the inner ring of the backup bearing is as follows: Figure 5 The inner ring 5 shown, and the outer ring of the backup bearing as shown Figure 5 The outer ring 3 shown, the bearing stator as... Figure 5 The bearing stator 2 shown; in the embodiment of the present invention, as... Figure 1 As shown, the control method for the magnetic levitation bearing includes: a process for realizing the levitation control of the magnetic levitation bearing, including steps S110 to S130.

[0043] In step S110, upon receiving a preset buoyancy command, the operating current of the bearing stator is controlled to cause the rotating shaft to move upward along the inner ring of the backup bearing to reach a first set position; wherein, the preset buoyancy command is a command used to control the buoyancy of the magnetic levitation bearing.

[0044] In step S120, if it is determined that the rotating shaft moves upward along the inner ring of the backup bearing to reach a first preset position, the operating current of the bearing stator is controlled to cause the rotating shaft to move downward to reach a second preset position to disengage from the clearance of the backup bearing; wherein, the first preset position is, for example, the position where the rotating shaft reaches the top of the inner ring of the backup bearing, the position where the rotating shaft reaches... Figure 6 and Figure 7 A position within the region between them, a position where the axis of rotation reaches the plane of symmetry along the Y1Y2 axis, etc. The second set position is as follows: Figure 7 The initial position is shown. The upward and downward movements of the rotating shaft are relative.

[0045] In step S130, if it is determined that the rotating shaft moves downward to a second set position to disengage from the clearance of the backup bearing, a preset floating shaft program is started to control the rotating shaft to levitate and realize the levitation control of the magnetic levitation bearing.

[0046] The proposed levitation control scheme for magnetic levitation bearings allows the bearing shaft to complete the levitation process from the upper end of the backup bearing downwards to the levitation position. This enables the shaft to completely detach from the clearance of the backup bearing before effective control of the magnetic levitation bearing is implemented. This ensures that the shaft remains stable and does not vibrate during the next levitation process (i.e., the shaft lifting process), thus ensuring stable levitation of the magnetic levitation bearing shaft and reducing the failure rate caused by levitation failure. This solves the problem that the magnetic levitation bearing shaft is prone to vibration and instability during the levitation phase.

[0047] In some embodiments, the control method for the magnetic levitation bearing described in the present invention further includes: determining the process of the rotating shaft moving upward to a first set position and / or moving downward to a second set position.

[0048] The following is combined Figure 2 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for determining whether the rotating shaft moves upward to reach a first set position and / or moves downward to reach a second set position. The specific process of determining whether the rotating shaft moves upward to reach a first set position and / or moves downward to reach a second set position includes: steps S210 to S230.

[0049] Step S210: Obtain the current position of the rotating shaft, such as by obtaining the position of the rotating shaft. Figure 5 The sensor shown indicates the current position of the rotating shaft as it moves upward along the inner ring of the backup bearing; for example, at least during the upward movement of the rotating shaft along the inner ring of the backup bearing and / or the downward movement of the rotating shaft, the current position of the rotating shaft is obtained, such as by obtaining the position of the rotating shaft as shown by the sensor ... Figure 5 The sensor shown indicates the current position of the rotating shaft as it moves upward along the inner ring of the backup bearing.

[0050] In step S220, when the rotating shaft is running upward along the inner ring of the backup bearing, it is determined whether the rotating shaft reaches a first preset position by running upward along the inner ring of the backup bearing based on the current position of the rotating shaft. If it is determined that the rotating shaft reaches the first preset position by running upward along the inner ring of the backup bearing, the operating current of the bearing stator is controlled to make the rotating shaft run downward to a second preset position to disengage from the clearance of the backup bearing. If it is determined that the rotating shaft does not reach the first preset position by running upward along the inner ring of the backup bearing, the process returns to the previous step to continue controlling the operating current of the bearing stator to make the rotating shaft reach the first preset position by running upward along the inner ring of the backup bearing.

[0051] And / or, in step S230, when the rotating shaft is running downwards, determine whether the rotating shaft meets the requirement of reaching a second preset position to disengage from the clearance of the backup bearing based on the current position of the rotating shaft; if it is determined that the rotating shaft meets the requirement of reaching a second preset position to disengage from the clearance of the backup bearing, then a preset floating shaft program is started to control the rotating shaft to levitate and realize the levitation control of the magnetic levitation bearing; if it is determined that the rotating shaft does not meet the requirement of reaching a second preset position, then return, and continue to control the operating current of the bearing stator to make the rotating shaft reach a second preset position to disengage from the clearance of the backup bearing.

[0052] The buoyancy control method of the magnetic levitation bearing in the relevant scheme is as follows: the rotating shaft of the magnetic levitation bearing completes the buoyancy process from the lower end of the backup bearing to the suspension position; the buoyancy control method of the magnetic levitation bearing adopted in the scheme of the present invention is as follows: the rotating shaft of the magnetic levitation bearing completes the buoyancy process from the upper end of the backup bearing downward to the suspension position.

[0053] In some embodiments, determining in step S120 that the rotating shaft has moved upward along the inner ring of the backup bearing to reach a first predetermined position includes:

[0054] Determine the position of the shaft when it travels upwards along the inner ring of the backup bearing and reaches the top of the inner ring of the backup bearing, where the top of the inner ring of the backup bearing is as follows: Figure 4 The minimum value detected by the Y1 direction sensor is the uppermost point of the inner ring of the backup bearing.

[0055] Figure 4 In the diagram, X1, X2, Y1, and Y2 are the defined coordinate directions. Figure 5 In the diagram, 1 represents a sensor (such as a position sensor), 2 represents the stator of the magnetic levitation bearing, 3 represents the outer ring of the backup bearing, 4 represents the balls of the backup bearing, 5 represents the inner ring of the backup bearing, and 6 represents the shaft of the magnetic levitation bearing. Figure 4 and Figure 5 As shown, the sensor outputs the minimum value when the shaft is close to X1 and the maximum value when the shaft is close to X2; similarly, the sensor outputs the minimum value when the shaft is close to Y1 and the maximum value when the shaft is close to Y2.

[0056] Figure 6 This is a schematic diagram of the position of the rotating shaft during its motion. Figure 7 This is a schematic diagram showing the movement position of the shaft as it moves to the upper end of the backup bearing. (See diagram below.) Figure 6 As shown, the bearing controller of the magnetic levitation bearing outputs a given current to the winding of the bearing stator, causing the bearing shaft to slowly move upwards along the inner ring of the backup bearing (e.g., upwards along the left inner wall or the right inner wall of the backup bearing's inner ring). During this time, the shaft remains close to the inner ring until it reaches the top of the backup bearing's inner ring. The shaft position is monitored in real time; the minimum value in the Y1 direction indicates the top of the backup bearing's inner ring. Figure 7 As shown. This type of shaft movement involves moving the shaft to the upper end of the inner ring of the backup bearing, preparing for the next step of resolving the problem of magnetic levitation bearing levitation failure caused by the clearance interference of the backup bearing. For details, please refer to the specific explanation of the two methods for disengaging the magnetic levitation bearing shaft from the clearance of the backup bearing.

[0057] In the solution of this invention, a corresponding current transformation method is used to rotate the shaft to the upper end of the backup bearing, so that the shaft moves downward from the upper end of the backup bearing until it is out of the clearance of the backup bearing before entering the floating shaft control program. This solves the problem of floating shaft failure caused by the clearance interference of the backup bearing. There are many ways to use the corresponding current transformation method to rotate the shaft to the upper end of the backup bearing. For example, it can be moved upward along the inner wall of the left side of the backup bearing, and X2 current and Y1 current can be applied. At the beginning, X2 current is larger and Y1 current is smaller. When the shaft reaches the left end of the backup bearing, Y1 current gradually increases while X2 current gradually decreases until the shaft reaches the upper end of the backup bearing.

[0058] In some embodiments, the two opposite directions in the horizontal coordinate of the coordinate system where the cross-section of the inner ring of the backup bearing is located are defined as X1 and X2, and the two opposite directions in the vertical coordinate are defined as Y1 and Y2. The shaft moves upward along the inner ring of the backup bearing, that is, the shaft moves along the inner ring of the backup bearing in the Y1 direction, and the shaft moves downward, that is, the shaft moves in the backup bearing in the Y2 direction.

[0059] Step S120, which determines that the rotating shaft has moved upward along the inner ring of the backup bearing to reach the first set position, further includes:

[0060] Determine that the rotating shaft moves upward along the inner ring of the backup bearing to any position in the plane of symmetry along the Y1Y2 axis.

[0061] Alternative embodiments

[0062] In this invention, the action of disengaging the clearance of the backup bearing is performed when the shaft reaches the highest point of the inner ring, and then the floating shaft program is executed. In an alternative embodiment, the action of disengaging the clearance of the backup bearing can also be performed without the shaft reaching the highest point; for example, the shaft reaches... Figure 6 and Figure 7 In the area between, the action of disengaging from the clearance of the backup bearing is performed, and then the floating shaft program is executed to achieve an effect similar to that of the present invention; or when the shaft reaches the symmetry plane along the Y1Y2 axis, the action of disengaging from the clearance of the backup bearing is performed, and then the floating shaft program is executed to achieve an effect similar to that of the present invention.

[0063] Once the shaft reaches the plane of symmetry along the Y1Y2 axis, it performs the action of disengaging from the clearance of the backup bearing, and then executes the floating shaft program. Specifically, in either the X1Y1 or X2Y1 region, the shaft can utilize its own gravity to disengage from the clearance of the backup bearing before entering the floating shaft program. Figure 6 and Figure 7 As shown, the shaft runs along the inner wall of the backup bearing from... Figures 6 to 7 The part is the X2Y1 region, and the region symmetrical about the axis of rotation along Y1Y2 is the X1Y1 region.

[0064] The main impact of the clearance of the backup bearing is that the weight of the shaft itself causes compression of the inner ring of the backup bearing after the shaft is lowered. As the shaft gradually rises during the levitation process of the magnetic levitation bearing, the elastic force generated by the clearance of the backup bearing is constantly changing. This introduces an uncertainty interference into the floating process of the magnetic levitation bearing, which may lead to failure of the floating shaft or vibration problems. The purpose of the present invention is to solve the problem of failure of the magnetic levitation bearing floating shaft caused by the clearance of the backup bearing.

[0065] This invention proposes a novel buoyancy control scheme for magnetic levitation bearings, which mainly addresses the problem of instability of the floating shaft caused by vibration during the buoyancy process of magnetic levitation bearings. It involves a method for how the central pivot shaft of the magnetic levitation bearing can disengage from the clearance of the backup bearing. The scheme of this invention can effectively avoid the problem of floating shaft vibration caused by the clearance of the backup bearing, and the scheme is simple to implement and usable.

[0066] In some embodiments, controlling the operating current of the bearing stator in step S120 to cause the shaft to move downwards to a second predetermined position to disengage from the clearance of the backup bearing includes: reducing the operating current of the bearing stator to disengage the shaft from the clearance of the backup bearing, specifically including:

[0067] The operating current of the bearing stator is reduced according to a preset reduction method, so that the rotating shaft moves downward to a second preset position to disengage from the clearance of the backup bearing; wherein, the preset reduction method is, for example, a gradual reduction. The second preset position is the position where the rotating shaft moves upward along the inner ring of the backup bearing to a first preset position and then moves downward until the rotating shaft disengages from the clearance of the backup bearing. For example, if the rotating shaft moves upward along the inner ring of the backup bearing to the first preset position, which is the position where the rotating shaft reaches the top of the inner ring of the backup bearing, the second preset position is the position of the rotating shaft when the distance between the rotating shaft and the top of the inner ring of the backup bearing is L; specifically, the position of the rotating shaft when the distance between the top of the cross-section of the rotating shaft and the top of the cross-section of the inner ring of the backup bearing is L. When the rotating shaft travels upwards along the inner ring of the backup bearing to reach a first predetermined position (i.e., any position within the plane of symmetry along the Y1Y2 axis), the second predetermined position is the position of the rotating shaft when the distance M between any position within the plane of symmetry along the Y1Y2 axis and the top of the rotating shaft's cross-section. The second predetermined position is the position reached when the rotating shaft begins its downward movement from the first predetermined position, directly downwards along the Y1Y2 axis, and is only subject to gravity and electromagnetic force, without the force of the backup bearing. The rotating shaft begins its downward movement from the first predetermined position, directly downwards along the Y1Y2 axis, until it reaches the second predetermined position; at the second predetermined position, the rotating shaft is only subject to gravity and electromagnetic force, with no force from the backup bearing.

[0068] The following provides illustrative examples of two methods for disengaging the shaft of a magnetic levitation bearing from the clearance of the backup bearing. .

[0069] The first method for disengaging the magnetic levitation bearing shaft from the clearance of the backup bearing is to gradually reduce the given current output by the bearing controller. During this reduction, the given current will pass a critical point (such as zero), at which point the shaft will be about to disengage from the inner ring of the backup bearing. At this point, the elastic force N of the magnetic levitation bearing on the shaft... 弹 =0N. For an active magnetic levitation bearing, the shaft gravity mg and the electromagnetic force F... e Equal, i.e., mg = F e For hybrid magnetic levitation bearings, the shaft gravity mg and electromagnetic force F e The equivalent magnetic field force F of a permanent magnet c The sum of these is equal: mg = F e +F c As the given current output by the bearing controller continues to decrease, the shaft will slowly move downwards until the distance from the shaft to the inner ring of the backup bearing is detected to be L. Figure 8As shown, it is determined that the shaft has completely disengaged from the clearance of the backup bearing, at which point the backup bearing's spring force no longer affects the shaft. The distance L varies depending on the backup bearing's clearance and magnetic force, and is on the order of micrometers.

[0070] This involves gradually decreasing the given current output by the bearing controller, meaning the bearing controller controls the reduction of the current output to the bearing stator windings. For example... Figure 7 The state shown (i.e., the shaft moves to the top of the inner ring of the backup bearing) necessitates that the magnetic levitation bearing force (i.e., magnetic levitation electromagnetic force) = backup bearing force (i.e., backup bearing spring force) + gravity (i.e., the weight of the shaft). Based on the magnetic levitation bearing force, the effective distance L for disengaging from the backup bearing's clearance is set downwards from the top of the backup bearing. The bearing controller reduces the output current to allow the shaft to disengage from the clearance before the floating shaft program is executed. Once the reduced output current of the bearing controller causes the shaft to fall to position L, the floating shaft control logic is activated to complete the floating shaft action. The simplified formula for calculating the magnetic levitation electromagnetic force F is as follows:

[0071] .

[0072] Where K is a preset calculation coefficient, i is the current in the stator winding of the bearing, and L0 is the gap (i.e., distance) between the magnetic bearing stator and rotor. For an active magnetic bearing, L = L0 + X0, where X0 is a preset redundancy. Figure 9 The suspension position of the intermediate shaft is its final suspension position. For hybrid magnetic bearings, the distance L from the shaft to the inner ring of the backup bearing can be set as follows: Figure 9 Half the clearance between the intermediate shaft and the inner ring of the backup bearing. Active bearings can also be judged using the same method as hybrid magnetic bearings (L). In practical applications, the probability of floating shaft failure due to clearance issues is relatively high in active bearings.

[0073] In the solution of the present invention, after the rotating shaft is rotated to the upper end of the backup bearing using the corresponding current transformation method, the shaft can be completely separated from the clearance of the backup bearing by its own gravity. Then, the floating shaft of the magnetic levitation bearing is controlled, which can ensure the stable levitation of the rotating shaft of the magnetic levitation bearing and reduce the failure rate caused by the failure of the floating shaft.

[0074] In some embodiments, step S120, controlling the operating current of the bearing stator to cause the shaft to move downwards to a second predetermined position to disengage from the clearance of the backup bearing, further includes: clearing the operating current of the bearing stator to disengage the shaft from the clearance of the backup bearing, specifically including:

[0075] The operating current of the bearing stator is controlled to zero, allowing the shaft to move downwards under its own weight to reach a second predetermined position and disengage from the clearance of the backup bearing. The second predetermined position is the position where the shaft moves upwards along the inner ring of the backup bearing to a first predetermined position and then moves downwards until it disengages from the clearance of the backup bearing. For example, if the first predetermined position is reached when the shaft moves upwards along the inner ring of the backup bearing to the top of the inner ring, the second predetermined position is the position of the shaft when the distance between the shaft and the top of the inner ring of the backup bearing is L. Specifically, it is the position of the shaft when the distance between the top of the shaft's cross-section and the top of the cross-section of the inner ring of the backup bearing is L. When the rotating shaft runs upward along the inner ring of the backup bearing to reach a first predetermined position, which is any position in the plane of symmetry along the Y1Y2 axis, the second predetermined position is the position of the rotating shaft when the distance between any position in the plane of symmetry along the Y1Y2 axis and the top of the cross-section of the rotating shaft is M.

[0076] The second method for disengaging the magnetic levitation bearing shaft from the clearance of the backup bearing: directly reset the given current output by the bearing controller to zero. At this time, due to the shaft's own gravity, the shaft will descend rapidly until the distance from the shaft to the inner ring of the backup bearing is detected as L. Figure 8 As shown, it can be determined that the shaft has completely disengaged from the clearance of the backup bearing. Figure 8 This is a schematic diagram of the process of the rotating shaft floating downwards from the top during the levitation of the magnetic levitation bearing. L is the distance at which the rotating shaft effectively disengages from the clearance of the backup bearing.

[0077] Two methods are employed to completely disengage the magnetic levitation bearing's shaft from the clearance of the backup bearing, aiming to eliminate the initial impact of the backup bearing's clearance on the magnetic levitation bearing's buoyancy. After the magnetic levitation bearing's shaft is completely disengaged from the backup bearing's clearance, [the following steps are taken]. Figure 8 The indicated position serves as the initial position for the magnetic levitation bearing to lift. The magnetic levitation bearing floating shaft program is then initiated. At this point, various floating shaft control methods are available, such as direct lifting, all of which can complete the floating shaft process and ultimately achieve stable levitation at the set position. Figure 9 As shown. Figure 9 This is a schematic diagram showing the levitation of the shaft to a set position during the levitation process of a magnetic levitation bearing.

[0078] Figure 10 This is a flowchart illustrating the levitation control method for magnetic levitation bearings. Figure 10 As shown, the levitation control method for magnetic levitation bearings includes:

[0079] Step 1: After receiving the buoyancy command for controlling the buoyancy of the magnetic levitation bearing shaft, the bearing controller of the magnetic levitation bearing executes Step 2.

[0080] Step 2: The bearing controller provides the bearing control current, that is, the bearing controller outputs the given current to the winding of the bearing stator so that the shaft moves upward along the inner ring of the backup bearing, and then steps 3 are executed.

[0081] Step 3: The shaft moves upward along the inner ring of the backup bearing, and then Step 4 is executed.

[0082] Step 4: Based on the position of the rotating shaft detected by the sensor, determine whether the rotating shaft has reached the top of the inner ring of the backup bearing. If yes, proceed to step 5; otherwise, return to step 2 and continue to give the bearing control current to the bearing controller so that the rotating shaft continues to move upward along the inner ring of the backup bearing.

[0083] Step 5: If it is determined that the shaft has reached the top of the inner ring of the backup bearing, the bearing control current is gradually reduced so that the shaft of the magnetic levitation bearing is disengaged from the clearance of the backup bearing, and then step 6 is executed.

[0084] In step 5, the bearing control current is gradually reduced so that the shaft of the magnetic levitation bearing is disengaged from the clearance of the backup bearing. Specifically, two methods can be used to disengage the shaft of the magnetic levitation bearing from the clearance of the backup bearing.

[0085] Step 6: Determine if the shaft has reached the set initial position: If yes, proceed to step 7; otherwise, return to step 5 to continue gradually reducing the bearing control current.

[0086] Step 7: Start the floating shaft program to bring the rotating shaft to the set position and successfully lift the magnetic levitation bearing.

[0087] The solution of this invention is essentially the control of the clearance of the backup bearing before initiating the magnetic levitation bearing floating shaft procedure. Disengaging the backup bearing clearance is a necessary stage before initiating the magnetic levitation bearing floating shaft procedure. In the related parties, all shafts float directly from the bottom. The impact of the backup bearing clearance on buoyancy was discovered by the inventors of this invention through practical application.

[0088] Some solutions address the potential failure of magnetic levitation bearings to rise due to the clearance of the backup bearing. These solutions require identifying the size of the backup bearing clearance, attempting to disengage the bearing from its bottom, and setting a height greater than or equal to the clearance as the first floating axis point to eliminate the clearance's influence. In this invention, the shaft is lowered from the top of the backup bearing to eliminate the clearance's effect. It eliminates the need to determine the backup bearing clearance size. A corresponding current transformation method is used to rotate the shaft to the top of the backup bearing, allowing it to descend from the top until it is free from the backup bearing's clearance before entering the floating axis control program. This solves the problem of floating axis failure caused by backup bearing clearance interference.

[0089] Using the technical solution of this embodiment, by controlling the buoyancy of the magnetic levitation bearing, upon receiving a buoyancy command, the current output by the bearing controller is controlled to cause the shaft to move upward along the inner ring of the backup bearing to a first set position (such as the shaft reaching the top of the inner ring of the backup bearing, the shaft reaching...). Figure 6 and Figure 7 (e.g., a position in the region between the axes, a position where the shaft reaches the plane of symmetry along the Y1Y2 axis), then reduce the current output of the bearing controller or clear the current output of the bearing controller to execute the action of disengaging from the clearance of the backup bearing, so that the shaft disengages from the clearance of the backup bearing and reaches the set initial position. After the shaft disengages from the clearance of the backup bearing, the floating shaft program of the magnetic levitation bearing is started to make the shaft reach the set position, thereby realizing the lifting and floating control of the magnetic levitation bearing; thus, by making the shaft move upward along the inner ring of the backup bearing and then downward when it is necessary to control the lifting and floating of the magnetic levitation bearing, until the shaft disengages from the clearance of the backup bearing and then the floating shaft program of the magnetic levitation bearing is executed, the shaft is ensured to float stably, so that the magnetic levitation bearing can float reliably.

[0090] According to an embodiment of the present invention, a control device for a magnetic levitation bearing, corresponding to a control method for magnetic levitation bearings, is also provided. See also Figure 3 The diagram shown is a structural schematic of an embodiment of the device of the present invention. The magnetic levitation bearing has a rotating shaft, a backup bearing, and a bearing stator, wherein the rotating shaft is as follows: Figure 5 The rotating shaft 6 shown has an inner ring and an outer ring, wherein the inner ring of the backup bearing is as follows: Figure 5 The inner ring 5 shown, and the outer ring of the backup bearing as shown Figure 5 The outer ring 3 shown, the bearing stator as... Figure 5 The bearing stator 2 shown; in the embodiment of the present invention, as... Figure 3 As shown, the control device for the magnetic levitation bearing includes: a control unit 104; the control unit 104 is used to implement the levitation control process of the magnetic levitation bearing, as follows:

[0091] The control unit 104 is configured to control the operating current of the bearing stator upon receiving a preset buoyancy command, so that the rotating shaft moves upward along the inner ring of the backup bearing to a first preset position; wherein the preset buoyancy command is a command used to control the buoyancy of the magnetic levitation bearing. The specific functions and processing of the control unit 104 are described in step S110.

[0092] The control unit 104 is further configured to, if it is determined that the rotating shaft has moved upward along the inner ring of the backup bearing to a first preset position, control the operating current of the bearing stator to cause the rotating shaft to move downward to a second preset position to disengage from the clearance of the backup bearing; wherein, the first preset position is, for example, the position where the rotating shaft reaches the top of the inner ring of the backup bearing, the position where the rotating shaft reaches... Figure 6 and Figure 7 A position within the region between them, a position where the axis of rotation reaches the plane of symmetry along the Y1Y2 axis, etc. The second set position is as follows: Figure 7 The initial position is shown. The upward and downward movements of the rotating shaft are relative. For the specific functions and processing of the control unit 104, please refer to step S120.

[0093] The control unit 104 is further configured to, if it is determined that the rotating shaft has moved downwards to a second preset position to disengage from the clearance of the backup bearing, initiate a preset floating shaft program to control the rotating shaft to levitate, thereby achieving the levitation control of the magnetic levitation bearing. The specific functions and processing of this control unit 104 are further described in step S130.

[0094] The proposed levitation control scheme for magnetic levitation bearings allows the bearing shaft to complete the levitation process from the upper end of the backup bearing downwards to the levitation position. This enables the shaft to completely detach from the clearance of the backup bearing before effective control of the magnetic levitation bearing is implemented. This ensures that the shaft remains stable and does not vibrate during the next levitation process (i.e., the shaft lifting process), thus ensuring stable levitation of the magnetic levitation bearing shaft and reducing the failure rate caused by levitation failure. This solves the problem that the magnetic levitation bearing shaft is prone to vibration and instability during the levitation phase.

[0095] In some embodiments, the control device for the magnetic levitation bearing described in the present invention further includes: an acquisition unit 102; the acquisition unit 102 and the control unit 104 are further configured to determine the process of the rotating shaft moving upward to a first preset position and / or moving downward to a second preset position, as detailed below:

[0096] The acquisition unit 102 is configured to acquire the current position of the rotating shaft, such as acquiring the position of the rotating shaft. Figure 5The sensor shown indicates the current position of the rotating shaft as it moves upward along the inner ring of the backup bearing; for example, at least during the upward movement of the rotating shaft along the inner ring of the backup bearing and / or the downward movement of the rotating shaft, the current position of the rotating shaft is obtained, such as by obtaining the position of the rotating shaft as shown by the sensor ... Figure 5 The sensor shown indicates the current position of the rotating shaft as it moves upward along the inner ring of the backup bearing. The specific functions and processing of this acquisition unit 102 are further described in step S210.

[0097] The control unit 104 is further configured to, when the rotating shaft is running upward along the inner ring of the backup bearing, determine, based on the current position of the rotating shaft, whether the rotating shaft has reached a first preset position by running upward along the inner ring of the backup bearing; if it is determined that the rotating shaft has reached the first preset position by running upward along the inner ring of the backup bearing, then the operating current of the bearing stator is controlled to cause the rotating shaft to run downward to a second preset position to disengage from the clearance of the backup bearing; if it is determined that the rotating shaft has not reached the first preset position by running upward along the inner ring of the backup bearing, then the process returns to continue controlling the operating current of the bearing stator to cause the rotating shaft to reach the first preset position by running upward along the inner ring of the backup bearing. The specific functions and processing of this control unit 104 are further described in step S220.

[0098] And / or, the control unit 104 is further configured to, when the rotating shaft is running downwards, determine, based on the current position of the rotating shaft, whether the downward running of the rotating shaft meets the requirement of reaching a second preset position to disengage from the clearance of the backup bearing; if it is determined that the downward running of the rotating shaft meets the requirement of reaching the second preset position to disengage from the clearance of the backup bearing, then a preset floating shaft program is initiated to control the rotating shaft to levitate, thereby realizing the levitation control of the magnetic levitation bearing; if it is determined that the downward running of the rotating shaft does not meet the requirement of reaching the second preset position, then the process returns, and if it continues, the operating current of the bearing stator is controlled to make the downward running of the rotating shaft reach the second preset position to disengage from the clearance of the backup bearing. The specific functions and processing of this control unit 104 are also described in step S230.

[0099] The buoyancy control method of the magnetic levitation bearing in the relevant scheme is as follows: the rotating shaft of the magnetic levitation bearing completes the buoyancy process from the lower end of the backup bearing to the suspension position; the buoyancy control method of the magnetic levitation bearing adopted in the scheme of the present invention is as follows: the rotating shaft of the magnetic levitation bearing completes the buoyancy process from the upper end of the backup bearing downward to the suspension position.

[0100] In some embodiments, the control unit 104 determines that the rotating shaft has moved upward along the inner ring of the backup bearing to a first predetermined position, including:

[0101] The control unit 104 is further configured to determine the position of the shaft when it travels upward along the inner ring of the backup bearing and reaches the top of the inner ring of the backup bearing, such that the top of the inner ring of the backup bearing is... Figure 4 The minimum value detected by the Y1 direction sensor is the uppermost point of the inner ring of the backup bearing.

[0102] Figure 4 In the diagram, X1, X2, Y1, and Y2 are the defined coordinate directions. Figure 5 In the diagram, 1 represents a sensor (such as a position sensor), 2 represents the stator of the magnetic levitation bearing, 3 represents the outer ring of the backup bearing, 4 represents the balls of the backup bearing, 5 represents the inner ring of the backup bearing, and 6 represents the shaft of the magnetic levitation bearing. Figure 4 and Figure 5 As shown, the sensor outputs the minimum value when the shaft is close to X1 and the maximum value when the shaft is close to X2; similarly, the sensor outputs the minimum value when the shaft is close to Y1 and the maximum value when the shaft is close to Y2.

[0103] Figure 6 This is a schematic diagram of the position of the rotating shaft during its motion. Figure 7 This is a schematic diagram showing the movement position of the shaft as it moves to the upper end of the backup bearing. (See diagram below.) Figure 6 As shown, the bearing controller of the magnetic levitation bearing outputs a given current to the winding of the bearing stator, causing the bearing shaft to slowly move upwards along the inner ring of the backup bearing (e.g., upwards along the left inner wall or the right inner wall of the backup bearing's inner ring). During this time, the shaft remains close to the inner ring until it reaches the top of the backup bearing's inner ring. The shaft position is monitored in real time; the minimum value in the Y1 direction indicates the top of the backup bearing's inner ring. Figure 7 As shown. This type of shaft movement involves moving the shaft to the upper end of the inner ring of the backup bearing, preparing for the next step of resolving the problem of magnetic levitation bearing levitation failure caused by the clearance interference of the backup bearing. For details, please refer to the specific explanation of the two methods for disengaging the magnetic levitation bearing shaft from the clearance of the backup bearing.

[0104] In the solution of the present invention, a corresponding current transformation method is used to rotate the shaft to the upper end of the backup bearing, so that the shaft moves downward from the upper end of the backup bearing until it is out of the clearance of the backup bearing before entering the floating shaft control program, thus solving the problem of floating shaft failure caused by the clearance interference of the backup bearing.

[0105] In some embodiments, the two opposite directions in the horizontal coordinate of the coordinate system where the cross-section of the inner ring of the backup bearing is located are defined as X1 and X2, and the two opposite directions in the vertical coordinate are defined as Y1 and Y2. The shaft moves upward along the inner ring of the backup bearing, that is, the shaft moves along the inner ring of the backup bearing in the Y1 direction, and the shaft moves downward, that is, the shaft moves in the backup bearing in the Y2 direction.

[0106] The control unit 104, which determines that the rotating shaft moves upward along the inner ring of the backup bearing to reach a first set position, further includes:

[0107] The control unit 104 is further configured to determine that the rotating shaft moves upward along the inner ring of the backup bearing to any position in the plane of symmetry along the Y1Y2 axis.

[0108] Alternative embodiments

[0109] In this invention, the action of disengaging the clearance of the backup bearing is performed when the shaft reaches the highest point of the inner ring, and then the floating shaft program is executed. In an alternative embodiment, the action of disengaging the clearance of the backup bearing can also be performed without the shaft reaching the highest point; for example, the shaft reaches... Figure 6 and Figure 7 In the area between, the action of disengaging from the clearance of the backup bearing is performed, and then the floating shaft program is executed to achieve an effect similar to that of the present invention; or when the shaft reaches the symmetry plane along the Y1Y2 axis, the action of disengaging from the clearance of the backup bearing is performed, and then the floating shaft program is executed to achieve an effect similar to that of the present invention.

[0110] When the shaft reaches the plane of symmetry along the Y1Y2 axis, it will perform the action of disengaging from the clearance of the backup bearing, and then execute the floating shaft program. Specifically, in the X1Y1 region or the X2Y1 region, the shaft can be disengaged from the clearance of the backup bearing due to its own gravity, and then enter the floating shaft program.

[0111] The main impact of the clearance of the backup bearing is that the weight of the shaft itself causes compression of the inner ring of the backup bearing after the shaft is lowered. As the shaft gradually rises during the levitation process of the magnetic levitation bearing, the elastic force generated by the clearance of the backup bearing is constantly changing. This introduces an uncertainty interference into the floating process of the magnetic levitation bearing, which may lead to failure of the floating shaft or vibration problems. The purpose of the present invention is to solve the problem of failure of the magnetic levitation bearing floating shaft caused by the clearance of the backup bearing.

[0112] This invention proposes a novel buoyancy control scheme for magnetic levitation bearings, which mainly addresses the problem of instability of the floating shaft caused by vibration during the buoyancy process of magnetic levitation bearings. It involves a method for how the central pivot shaft of the magnetic levitation bearing can disengage from the clearance of the backup bearing. The scheme of this invention can effectively avoid the problem of floating shaft vibration caused by the clearance of the backup bearing, and the scheme is simple to implement and usable.

[0113] In some embodiments, the control unit 104 controls the operating current of the bearing stator to cause the shaft to move downwards to a second predetermined position to disengage from the clearance of the backup bearing. This includes reducing the operating current of the bearing stator to disengage the shaft from the clearance of the backup bearing, as detailed below:

[0114] The control unit 104 is further configured to control the operating current of the bearing stator to decrease according to a preset reduction method, so that the rotating shaft moves downward to a second preset position to disengage from the clearance of the backup bearing; wherein, the preset reduction method is, for example, a gradual reduction method. The second preset position is the position where the rotating shaft moves upward along the inner ring of the backup bearing to a first preset position and then moves downward until the rotating shaft disengages from the clearance of the backup bearing. For example, if the rotating shaft moves upward along the inner ring of the backup bearing to the first preset position, which is the position where the rotating shaft moves upward along the inner ring of the backup bearing to the top of the inner ring, the second preset position is the position of the rotating shaft when the distance between the rotating shaft and the top of the inner ring of the backup bearing is L; specifically, the position of the rotating shaft when the distance between the top of the cross-section of the rotating shaft and the top of the cross-section of the inner ring of the backup bearing is L. When the rotating shaft runs upward along the inner ring of the backup bearing to reach a first predetermined position, which is any position in the plane of symmetry along the Y1Y2 axis, the second predetermined position is the position of the rotating shaft when the distance between any position in the plane of symmetry along the Y1Y2 axis and the top of the cross-section of the rotating shaft is M.

[0115] The following provides illustrative examples of two methods for disengaging the shaft of a magnetic levitation bearing from the clearance of the backup bearing. .

[0116] The first method for disengaging the magnetic levitation bearing shaft from the clearance of the backup bearing is to gradually reduce the given current output by the bearing controller. During this reduction, the given current will pass a critical point (such as zero), at which point the shaft will be about to disengage from the inner ring of the backup bearing. At this point, the elastic force N of the magnetic levitation bearing on the shaft... 弹 =0N. For an active magnetic levitation bearing, the shaft gravity mg and the electromagnetic force F... e Equal, i.e., mg = F e For hybrid magnetic levitation bearings, the shaft gravity mg and electromagnetic force F e The equivalent magnetic field force F of a permanent magnet c The sum of these is equal: mg = F e +F c As the given current output by the bearing controller continues to decrease, the shaft will slowly move downwards until the distance from the shaft to the inner ring of the backup bearing is detected to be L. Figure 8 As shown, it is determined that the shaft has completely disengaged from the clearance of the backup bearing, and at this point, there is no longer any influence of the backup bearing's spring force on the shaft.

[0117] This involves gradually decreasing the given current output by the bearing controller, meaning the bearing controller controls the reduction of the current output to the bearing stator windings. For example... Figure 7The state shown (i.e., the shaft moves to the top of the inner ring of the backup bearing) necessitates that the magnetic levitation bearing force equals the backup bearing force plus gravity. Based on the magnetic levitation bearing force, a distance L is set from the top of the backup bearing downwards to effectively disengage from its clearance. The bearing controller reduces the output current to allow the shaft to escape the clearance effect before the floating shaft program is executed. Once the reduced output current of the bearing controller causes the shaft to fall to position L, the floating shaft control logic is activated to complete the floating shaft action.

[0118] In the solution of the present invention, after the rotating shaft is rotated to the upper end of the backup bearing using the corresponding current transformation method, the shaft can be completely separated from the clearance of the backup bearing by its own gravity. Then, the floating shaft of the magnetic levitation bearing is controlled, which can ensure the stable levitation of the rotating shaft of the magnetic levitation bearing and reduce the failure rate caused by the failure of the floating shaft.

[0119] In some embodiments, the control unit 104 controls the operating current of the bearing stator to cause the shaft to move downwards to a second predetermined position to disengage from the clearance of the backup bearing. The control unit further includes a process of clearing the operating current of the bearing stator to disengage the shaft from the clearance of the backup bearing, as detailed below:

[0120] The control unit 104 is further configured to control the operating current of the bearing stator to zero, so that the rotating shaft moves downwards under its own weight to a second predetermined position to disengage from the clearance of the backup bearing. The second predetermined position is the position where the rotating shaft moves upwards along the inner ring of the backup bearing to a first predetermined position and then moves downwards until it disengages from the clearance of the backup bearing. For example, if the first predetermined position is the position where the rotating shaft moves upwards along the inner ring of the backup bearing to the top of the inner ring, the second predetermined position is the position of the rotating shaft when the distance between the rotating shaft and the top of the inner ring of the backup bearing is L; specifically, it is the position of the rotating shaft when the distance between the top of the cross-section of the rotating shaft and the top of the cross-section of the inner ring of the backup bearing is L. When the rotating shaft runs upward along the inner ring of the backup bearing to reach a first predetermined position, which is any position in the plane of symmetry along the Y1Y2 axis, the second predetermined position is the position of the rotating shaft when the distance between any position in the plane of symmetry along the Y1Y2 axis and the top of the cross-section of the rotating shaft is M.

[0121] The second method for disengaging the magnetic levitation bearing shaft from the clearance of the backup bearing: directly reset the given current output by the bearing controller to zero. At this time, due to the shaft's own gravity, the shaft will descend rapidly until the distance from the shaft to the inner ring of the backup bearing is detected as L. Figure 8 As shown, it can be determined that the shaft has completely disengaged from the clearance of the backup bearing. Figure 8 This is a schematic diagram of the process of the rotating shaft floating downwards from the top during the levitation of the magnetic levitation bearing. L is the distance at which the rotating shaft effectively disengages from the clearance of the backup bearing.

[0122] Two methods are employed to completely disengage the magnetic levitation bearing's shaft from the clearance of the backup bearing, aiming to eliminate the initial impact of the backup bearing's clearance on the magnetic levitation bearing's buoyancy. After the magnetic levitation bearing's shaft is completely disengaged from the backup bearing's clearance, [the following steps are taken]. Figure 8 The indicated position serves as the initial position for the magnetic levitation bearing to lift. The magnetic levitation bearing floating shaft program is then initiated. At this point, various floating shaft control methods are available, such as direct lifting, all of which can complete the floating shaft process and ultimately achieve stable levitation at the set position. Figure 9 As shown. Figure 9 This is a schematic diagram showing the levitation of the shaft to a set position during the levitation process of a magnetic levitation bearing.

[0123] Figure 10 This is a flowchart illustrating the levitation control method for magnetic levitation bearings. Figure 10 As shown, the levitation control method for magnetic levitation bearings includes:

[0124] Step 1: After receiving the buoyancy command for controlling the buoyancy of the magnetic levitation bearing shaft, the bearing controller of the magnetic levitation bearing executes Step 2.

[0125] Step 2: The bearing controller provides the bearing control current, that is, the bearing controller outputs the given current to the winding of the bearing stator so that the shaft moves upward along the inner ring of the backup bearing, and then steps 3 are executed.

[0126] Step 3: The shaft moves upward along the inner ring of the backup bearing, and then Step 4 is executed.

[0127] Step 4: Based on the position of the rotating shaft detected by the sensor, determine whether the rotating shaft has reached the top of the inner ring of the backup bearing. If yes, proceed to step 5; otherwise, return to step 2 and continue to give the bearing control current to the bearing controller so that the rotating shaft continues to move upward along the inner ring of the backup bearing.

[0128] Step 5: If it is determined that the shaft has reached the top of the inner ring of the backup bearing, the bearing control current is gradually reduced so that the shaft of the magnetic levitation bearing is disengaged from the clearance of the backup bearing, and then step 6 is executed.

[0129] In step 5, the bearing control current is gradually reduced so that the shaft of the magnetic levitation bearing is disengaged from the clearance of the backup bearing. Specifically, two methods can be used to disengage the shaft of the magnetic levitation bearing from the clearance of the backup bearing.

[0130] Step 6: Determine if the shaft has reached the set initial position: If yes, proceed to step 7; otherwise, return to step 5 to continue gradually reducing the bearing control current.

[0131] Step 7: Start the floating shaft program to bring the rotating shaft to the set position and successfully lift the magnetic levitation bearing.

[0132] The solution of this invention is essentially the control of the clearance of the backup bearing before initiating the magnetic levitation bearing floating shaft procedure. Disengaging the backup bearing clearance is a necessary stage before initiating the magnetic levitation bearing floating shaft procedure. In the related parties, all shafts float directly from the bottom. The impact of the backup bearing clearance on buoyancy was discovered by the inventors of this invention through practical application.

[0133] Some solutions address the potential failure of magnetic levitation bearings to rise due to the clearance of the backup bearing. These solutions require identifying the size of the backup bearing clearance, attempting to disengage the bearing from its bottom, and setting a height greater than or equal to the clearance as the first floating axis point to eliminate the clearance's influence. In this invention, it is unnecessary to determine the backup bearing clearance. A corresponding current transformation method is used to rotate the shaft to the upper end of the backup bearing, causing the shaft to descend from the upper end until it disengages from the backup bearing's clearance before entering the floating axis control program. This solves the problem of floating axis failure caused by backup bearing clearance interference.

[0134] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0135] According to an embodiment of the present invention, a magnetic levitation bearing system corresponding to a control device for a magnetic levitation bearing is also provided. This magnetic levitation bearing system may include the control device for the magnetic levitation bearing described above.

[0136] Since the processing and functions implemented by the magnetic levitation bearing system in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned devices, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0137] According to an embodiment of the present invention, a computer program product corresponding to the control method for magnetic levitation bearings is also provided, comprising a computer program that, when executed by a processor, implements the steps of the control method for magnetic levitation bearings described above.

[0138] Since the processing and functions implemented by the product in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0139] According to an embodiment of the present invention, a storage medium corresponding to a control method for a magnetic levitation bearing is also provided. The storage medium includes a stored program, wherein, when the program is executed, the device where the storage medium is located executes the steps of the control method for the magnetic levitation bearing described above.

[0140] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0141] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0142] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for a magnetic levitation bearing, characterized in that, The magnetic levitation bearing has a rotating shaft, a backup bearing, and a bearing stator; the control method of the magnetic levitation bearing includes: Upon receiving a preset buoyancy command, the operating current of the bearing stator is controlled to cause the rotating shaft to move upward along the inner ring of the backup bearing to reach a first preset position; wherein, the preset buoyancy command is a command used to control the buoyancy of the magnetic levitation bearing; If it is determined that the rotating shaft runs upward along the inner ring of the backup bearing to reach a first set position, then the operating current of the bearing stator is controlled so that the rotating shaft runs downward to reach a second set position. If it is determined that the rotating shaft has reached the second set position by moving downwards, a preset floating shaft program is started to control the rotating shaft to levitate and realize the levitation control of the magnetic levitation bearing.

2. The control method for a magnetic levitation bearing according to claim 1, characterized in that, Also includes: Obtain the current position of the rotating shaft; Based on the current position of the rotating shaft, determine whether the rotating shaft can move upward along the inner ring of the backup bearing to reach the first set position; If it is determined that the shaft does not reach the first set position by moving upward along the inner ring of the backup bearing, the operation is reversed to continue controlling the operating current of the bearing stator so that the shaft moves upward along the inner ring of the backup bearing to reach the first set position. And / or, based on the current position of the shaft, determine whether the shaft can reach a second set position by moving downwards; if it is determined that the shaft cannot reach the second set position by moving downwards, return to the previous position, and then control the operating current of the bearing stator to make the shaft move downwards to the second set position.

3. The control method for a magnetic levitation bearing according to claim 1 or 2, characterized in that, Determining that the rotating shaft travels upward along the inner ring of the backup bearing to reach a first predetermined position includes: Determine the position of the shaft when it travels upward along the inner ring of the backup bearing and reaches the top of the inner ring of the backup bearing.

4. The control method for a magnetic levitation bearing according to claim 1 or 2, characterized in that, Let the two opposite directions in the abscissa of the cross section of the inner ring of the backup bearing be the X1 direction and the X2 direction, and the two opposite directions in the ordinate be the Y1 direction and the Y2 direction; Determining that the rotating shaft runs upward along the inner ring of the backup bearing to reach a first predetermined position further includes: Determine that the rotating shaft moves upward along the inner ring of the backup bearing to any position in the plane of symmetry along the Y1Y2 axis.

5. The control method for a magnetic levitation bearing according to any one of claims 1 to 4, characterized in that, Controlling the operating current of the bearing stator to cause the rotor to move downwards to a second predetermined position includes: The operating current of the bearing stator is reduced according to a preset reduction method, so that the rotor moves downward to reach the second preset position; The second set position is the position where the rotating shaft moves upward along the inner ring of the backup bearing to the first set position and then moves downward until the rotating shaft disengages from the clearance of the backup bearing.

6. The control method for a magnetic levitation bearing according to any one of claims 1 to 4, characterized in that, Controlling the operating current of the bearing stator to cause the rotor to move downwards to a second predetermined position further includes: The operating current of the bearing stator is controlled to be zero so that the shaft moves downwards to the second set position by its own weight. The second set position is the position where the rotating shaft moves upward along the inner ring of the backup bearing to the first set position and then moves downward until the rotating shaft disengages from the clearance of the backup bearing.

7. A control device for a magnetic levitation bearing, characterized in that, The magnetic levitation bearing has a rotating shaft, a backup bearing, and a bearing stator; the control device for the magnetic levitation bearing includes: The control unit is configured to control the operating current of the bearing stator upon receiving a preset buoyancy command, so that the rotating shaft moves upward along the inner ring of the backup bearing to a first preset position; wherein the preset buoyancy command is a command used to control the buoyancy of the magnetic levitation bearing. The control unit is further configured to, if it is determined that the rotating shaft moves upward along the inner ring of the backup bearing to reach a first set position, control the operating current of the bearing stator to cause the rotating shaft to move downward to reach a second set position. The control unit is also configured to, if it is determined that the rotating shaft has moved downward to a second set position, initiate a preset floating shaft program to control the rotating shaft to levitate and realize the levitation control of the magnetic levitation bearing.

8. A magnetic levitation bearing system, characterized in that, include: The control device for the magnetic levitation bearing as described in claim 7.

9. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method for the magnetic levitation bearing as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method for the magnetic levitation bearing as described in any one of claims 1 to 6.

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