Magnetic fluid double suspension bearing and control system

Abstract

The application relates to a magnetic-liquid double-suspension bearing and a control system, belonging to the technical field of active electromagnetic bearings, liquid static pressure supporting and control, which comprises a rotating shaft, a retainer, an axial sensing unit, a first axial balancing unit, a first radial bearing unit, a first radial sensing unit, a second radial sensing unit, a second radial bearing unit, a second axial balancing unit and a power unit. The application replaces the thrust disc structure of a conventional bearing with two axial balancing units and adds a permanent magnetic supporting part. Removing the thrust disc structure can avoid the shaft warping caused by the deformation of the thrust disc structure due to temperature rise, improve the working precision of the bearing, reduce the impact and friction of the rotating shaft, increase the service life of the bearing and achieve the purpose of protecting the bearing.

Description

Technical Field

[0001] This invention belongs to the field of bearing and control technology, and specifically relates to a magnetic fluid double suspension bearing and its control system. Background Technology

[0002] Magnetic-hydraulic double-suspension bearings are a new type of suspension bearing primarily designed for radial loads. They possess advantages such as good radial stiffness and vibration resistance, thus gaining widespread attention and application. However, their axial balance is achieved by using a thrust disc structure to provide axial force, which makes the overall system structure more complex and difficult to install, debug, disassemble, and maintain. Furthermore, with the development of global industry, in applications requiring high precision, they exhibit the following drawbacks:

[0003] 1. Low precision in bearing adjustment and installation;

[0004] 2. The bearing installation was complicated and a lot of manpower and resources were wasted;

[0005] 3. The bearings have low working precision and short service life. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a magnetic-hydraulic dual-suspension bearing and its control system. It utilizes two axial balancing units to replace the thrust plate structure of traditional bearings, improving bearing adjustment and installation accuracy, simplifying bearing maintenance and installation procedures, avoiding damage such as shaft warping caused by temperature rise and thrust plate deformation, thus improving bearing working accuracy and extending bearing service life. Furthermore, this invention incorporates a permanent magnet anti-drop design, preventing the bearing from directly falling when the electro-hydraulic support malfunctions, thereby reducing shaft impact and wear, increasing bearing service life, and achieving the goal of bearing protection.

[0007] To achieve the above objectives, the present invention discloses the following technical solution:

[0008] Specifically, the present invention provides a magnetic-hydraulic dual-suspension bearing, comprising a rotating shaft, a cage, an axial sensing unit, a first axial balancing unit, a first radial bearing unit, a first radial sensing unit, a second radial sensing unit, a second radial bearing unit, a second axial balancing unit, and a power unit; the axial sensing unit, the first axial balancing unit, the first radial bearing unit, the first radial sensing unit, the second radial sensing unit, the second radial bearing unit, the second axial balancing unit, and the power unit are sequentially sleeved on the rotating shaft; the cage is disposed below the rotating shaft and connected to the first radial bearing unit and the second radial bearing unit respectively, and the cage includes a first cage and a second cage; the axial sensing unit is connected to a first end of the first balancing unit housing of the first axial balancing unit, and the second end of the first balancing unit housing is connected to the first radial bearing unit; the first axial balancing unit includes a first retaining ring, a first axial thrust core, a first magnetic isolation ring, and a... The system comprises a first coil frame, a first axial electromagnetic coil, and a first balancing unit housing; the first axial thrust core is sleeved on the outside of the first end of the rotating shaft, the first coil frame is sleeved on the outside of the first axial thrust core, the first retaining ring is sleeved on the outside of the first end of the rotating shaft, and one side of the first retaining ring contacts the first end of the first axial thrust core, the first magnetic shielding ring is disposed on the outside of the first end of the rotating shaft and contacts the second end of the first axial thrust core, the first balancing unit housing is sleeved on the outside of the first coil frame, and there is a first electromagnetic coil mounting space for mounting the first axial electromagnetic coil between the first balancing unit housing and the first coil frame, and the first axial electromagnetic coil is disposed within the first electromagnetic coil mounting space; the first radial bearing unit includes a first magnetic sleeve, a second magnetic shielding ring, a first anti-drop permanent magnet ring, a first coil, a first stator, a first anti-drop permanent magnet support, a first magnetic shielding retainer, and a second retaining ring;The first magnetic sleeve is sleeved on the outside of the first end of the rotating shaft, and the first end of the first magnetic sleeve contacts the first magnetic isolation ring. The second end of the first magnetic sleeve contacts the second magnetic isolation ring, which is located on the outside of the first end of the rotating shaft. The first anti-drop permanent magnet ring is sleeved on the outside of the first end of the rotating shaft, and the first end of the first anti-drop permanent magnet ring contacts the second magnetic isolation ring. The second end of the first anti-drop permanent magnet ring contacts the first shoulder of the rotating shaft. A plurality of first coils are arranged on the outside of the first magnetic sleeve, and the first coils are fixedly connected to the stator column of the first stator. The first anti-drop permanent magnet support is sleeved on the first anti-drop support. The first anti-drop permanent magnet support body is fixedly connected to the first magnetic isolation retainer on the outside of the first anti-drop permanent magnet ring. The first magnetic isolation retainer is sleeved on the outside of the first anti-drop permanent magnet ring. The first stator is sleeved on the outside of the first coil, the first anti-drop permanent magnet support body, and the first magnetic isolation retainer. The first end of the first stator is connected to the first balance unit housing, and the second end of the first stator is connected to the first retainer. The interior of the first stator is provided with a plurality of stator columns for connecting the first coil. The first magnetic isolation retainer is connected to the first stator through the second retaining ring. The second radial bearing unit includes a second magnetic sleeve, a third magnetic isolation ring, and a second anti-drop permanent magnet ring. The system comprises a magnetic ring, a second coil, a second stator, a second anti-drop permanent magnet support, a second magnetic isolation retainer, and a third retaining ring. The second magnetic sleeve is fitted onto the outside of the second end of the rotating shaft, with its first end contacting the second shoulder of the shaft and its second end contacting the third magnetic isolation ring. Both the third magnetic isolation ring and the second anti-drop permanent magnet ring are located outside the second end of the rotating shaft, with the first end of the second anti-drop permanent magnet ring contacting the third magnetic isolation ring and its second end contacting the second axial balance unit. Multiple second coils are arranged outside the second magnetic sleeve, and the second coils are fixed to the stator columns inside the second stator. The second anti-fall permanent magnet support is sleeved on the outside of the second anti-fall permanent magnet ring, and the second anti-fall permanent magnet support is fixedly connected to the second magnetic isolation retainer. The second magnetic isolation retainer is sleeved on the outside of the second anti-fall permanent magnet ring. The second stator is sleeved on the outside of the second coil, the second anti-fall permanent magnet support, and the second magnetic isolation retainer. The first end of the second stator is connected to the second end cover, and the second end of the second stator is connected to the second retainer. The second axial balance unit includes a fourth magnetic isolation ring, a second axial thrust core, a fourth retaining ring, a fourth sealing ring, a second coil frame, a second axial electromagnetic coil, a second balance unit housing, and a cover.The fourth magnetic isolation ring, the second axial thrust core, and the fourth retaining ring are all sleeved on the outside of the second end of the rotating shaft. The fourth magnetic isolation ring and the fourth retaining ring are respectively disposed at both ends of the second axial thrust core, and the fourth magnetic isolation ring is in contact with the second end of the second anti-drop permanent magnet ring. The second coil frame is sleeved on the outside of the second axial thrust core and the fourth retaining ring. The second balancing unit housing is sleeved on the outside of the second coil frame, and there is a second electromagnetic coil mounting space between the second balancing unit housing and the second coil frame. The second axial electromagnetic coil is disposed within the second electromagnetic coil mounting space.

[0009] Preferably, the axial sensing unit includes a first displacement sensor and a first sensor holder. The first displacement sensor is disposed at the center of the first surface of the first sensor holder, and the detection point of the first displacement sensor is aligned with the end face of the first end of the rotating shaft. The second end of the first sensor holder is connected to the housing of the first balance unit.

[0010] Preferably, the first radial sensing unit includes a first end cap, a second sensor holder, and a second displacement sensor. The first side of the first end cap is connected to one end of the first holder, and the second sensor holder is provided on the second side of the first end cap. Four second displacement sensors are evenly distributed on the second sensor holder, and the detection points of the second displacement sensors are aligned with the direction of rotation.

[0011] Preferably, the second radial sensing unit includes a third displacement sensor, a third sensor holder, and a second end cap. The second side of the second end cap is connected to the first end of the second stator. The first side of the second end cap is provided with a third sensor holder. Four third displacement sensors are evenly arranged on the third sensor holder, and the detection points of the third displacement sensors are aligned with the direction of the rotation axis.

[0012] Preferably, it further includes a first sealing ring, a second sealing ring, a third sealing ring, and a fourth sealing ring. The first sealing ring is disposed at the connection between the first coil frame and the rotating shaft, and the first end of the first sealing ring contacts the first end of the first sensor holder. The second sealing ring is disposed at the connection between the first end cover and the rotating shaft to prevent leakage of internal oil. The third sealing ring is disposed at the connection between the second end cover and the rotating shaft to prevent leakage of internal oil. The fourth sealing ring is disposed at the connection between the second coil frame and the rotating shaft, and the first end of the fourth sealing ring contacts the first end of the cover.

[0013] Preferably, the retainer is further provided with a retaining plate, and both the first retainer and the second retainer are disposed above the retaining plate and are perpendicular to the retaining plate.

[0014] Preferably, the power unit is hinged to the second end of the rotating shaft and drives the rotating shaft to rotate.

[0015] Preferably, in the working state, the first retaining ring, the first axial thrust iron core, the first magnetic isolation ring, the first magnetic conductive sleeve, the second magnetic isolation ring, the first anti-drop permanent magnet ring, the second magnetic conductive sleeve, the third magnetic isolation ring, the second anti-drop permanent magnet ring, the fourth magnetic isolation ring, the second axial thrust iron core, and the fourth retaining ring rotate with the rotation of the rotating shaft.

[0016] Preferably, the installation includes the following steps: S1, assembling and installing the radial bearing unit; S2, assembling and installing the rotating shaft; S3, assembling and installing the axial balance unit; S4, installing the axial sensing unit and the radial sensing unit; S5, fixing the power unit to the right side of the right balance unit housing with bolts, the bolt heads entering the countersunk holes on the right balance unit housing.

[0017] On the other hand, the present invention also provides a control system for a magnetic fluid dual suspension bearing, wherein the axial balance unit control part adopts a closed-loop negative feedback control strategy, and its control process includes the following steps:

[0018] S1. Set the axial reference position of the shaft, which meets the axial position required for the shaft to operate normally;

[0019] S2. Interference such as axial load is applied to the shaft, causing axial displacement of the shaft;

[0020] S3. The axial displacement sensor detects the change in the axial position of the rotating shaft and obtains the axial deviation displacement data by comparing it with the set axial reference position;

[0021] S4. The axial displacement sensor inputs the obtained axial deviation displacement into the PID controller;

[0022] S5, then the output signal is converted from digital to analog and sent to two power amplifiers;

[0023] S6, the power amplifier outputs current to the axial electromagnetic coil of the first axial balancing unit and the axial electromagnetic coil of the right axial balancing unit, respectively;

[0024] S7. When the coil is energized, it generates a magnetic field that causes the first axial balancing unit and the second axial balancing unit to generate forces in the left and right directions, respectively.

[0025] S8. The axial position of the rotating shaft is adjusted by two axial thrust iron cores fixed on the rotating shaft;

[0026] S9: Closed-loop negative feedback control achieves dynamic balance, and the shaft is maintained at the axial reference position.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The design and installation method of the present invention can simplify the bearing installation and disassembly steps; the shaft and the fixed parts thereon can be disassembled as a whole without disassembling the first radial bearing unit and the second radial bearing unit, avoiding the complicated debugging required for reinstalling the stator and the first cage of the first radial bearing unit and the stator and the second cage of the second radial bearing unit.

[0029] (2) The present invention eliminates the push plate on the transmission structure, thereby avoiding the phenomenon of shaft warping caused by the deformation of the thrust plate due to temperature rise, improving the working accuracy of the bearing and extending the service life of the bearing; the anti-drop permanent magnet support and anti-drop permanent magnet ring added to the first radial bearing unit and the second radial bearing unit generate support force to balance the weight of the shaft itself. When the electro-hydraulic support of the bearing fails, it can prevent the bearing from falling directly, thereby reducing the impact of shaft falling and increasing the service life of the bearing, and achieving the purpose of protecting the bearing. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the magnetic fluid double suspension bearing of the present invention;

[0031] Figure 2 This is a three-dimensional cross-sectional view of the main structure of the magnetic fluid dual suspension bearing of the present invention;

[0032] Figure 3 This is a half-sectional schematic diagram of the main structure of the magnetic fluid double suspension bearing of the present invention;

[0033] Figure 4a and Figure 4b This is a schematic diagram of the radial bearing unit of the magnetic fluid double suspension bearing of the present invention;

[0034] Figure 5 This is a schematic diagram of the axial balancing unit of the magnetic fluid double suspension bearing of the present invention;

[0035] Figure 6 The system control diagram of the magnetic fluid dual suspension bearing of the present invention.

[0036] The following are descriptions of some of the attached figures:

[0037] 1-Axial sensing unit; 101-First displacement sensor; 102-First sensor holder; 2-First axial balancing unit; 201-First sealing ring; 202-First retaining ring; 203-First axial thrust core; 204-First magnetic shielding ring; 205-First coil frame; 206-First axial electromagnetic coil; 207-First balancing unit housing; 3-First radial bearing unit; 301-First magnetic sleeve; 302-Second magnetic shielding ring; 303-First anti-drop permanent magnet ring; 304-First coil; 305-First stator; 306-First anti-drop permanent magnet support; 307-First magnetic shielding holder; 308-Second retaining ring; 4-First radial sensing unit; 401-First end cap; 402-Second sensor holder; 403-Second displacement sensor; 404-Second sealing ring; 5-Rotating shaft; 6 - Second radial sensing unit; 601- Third displacement sensor; 602- Third sensor holder; 603- Second end cap; 604- Third sealing ring; 7- Second radial bearing unit; 701- Second magnetic sleeve; 702- Third magnetic isolation ring; 703- Second anti-drop permanent magnet ring; 704- Second coil; 705- Second stator; 706- Second anti-drop permanent magnet support; 707- Second magnetic isolation holder; 708- Third retaining ring; 8- Second axial balance unit; 801- Fourth magnetic isolation ring; 802- Second axial thrust core; 803- Fourth retaining ring; 804- Fourth sealing ring; 805- Second coil holder; 806- Second axial electromagnetic coil; 807- Second balance unit housing; 808- Cover; 9- Holder; 901- First holder; 902- Second holder; 10- Power unit. Detailed Implementation

[0038] Exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0039] This invention provides a magnetic fluid dual suspension bearing and a control system, such as Figure 1 , Figure 2 and Figure 3 As shown, a magnetic fluid dual suspension bearing system structure includes an axial sensing unit 1, a first axial balancing unit 2, a first radial bearing unit 3, a first radial sensing unit 4, a rotating shaft 5, a second radial sensing unit 6, a second radial bearing unit 7, a second axial balancing unit 8, a cage 9, and a power unit 10.

[0040] The first axial balancing unit 2 and the second axial balancing unit 8 in this application replace the traditional thrust plate structure, avoiding damage such as shaft warping caused by temperature rise and deformation of the traditional thrust plate. They use two electromagnetic forces of adjustable magnitude in opposite directions to balance the axial force.

[0041] The axial sensing unit 1 is designed to sense the deviation of the axial displacement of the rotating shaft and input it to the control system to adjust the axial balancing force, which is a supporting design for balancing the axial force.

[0042] The first radial bearing unit 3 and the second radial bearing unit 7 provide radial support and prevent falling.

[0043] The first coil 304 or the second coil 704 is energized to generate a magnetic field, which causes the first stator 305 or the second stator 705 to generate an electromagnetic force with the first magnetic sleeve 301 or the second magnetic sleeve 701. The electromagnetic force causes the rotating shaft and the workpiece fixed on it to levitate, and the connected power unit causes the rotating shaft and the workpiece fixed on it to rotate.

[0044] The eight oil ports are located on the eight magnetic poles, which are the stator columns of the first and second stators, enabling the hydraulic system to enter and exit oil. The oil flows through the magnetic sleeve to form an oil film, supporting the rotating shaft.

[0045] The first coil 304 and the second coil 704 on the first radial bearing unit 3 and the second radial bearing unit 7 are energized to generate a magnetic field, which causes the stator column and the magnetic sleeve to generate electromagnetic force; oil flows in from the stator column and flows through the first magnetic sleeve 301 and the second magnetic sleeve 701, thereby generating static pressure support force, making the device work more stably.

[0046] The first anti-drop permanent magnet support 306 or the second anti-drop permanent magnet support 706 generates a repulsive force with the first anti-drop permanent magnet ring 303 or the second anti-drop permanent magnet ring 703, providing partial support force for the rotating shaft. When the electromagnetic support or hydrostatic support is damaged, the design of the first anti-drop permanent magnet support 306 or the second anti-drop permanent magnet support 706 and the first anti-drop permanent magnet ring 303 or the second anti-drop permanent magnet ring 703 can provide buffer force and adjustment time, ensuring that the rotating shaft does not fall during electromagnetic or hydrostatic adjustment.

[0047] The first radial sensing unit 4 and the second radial sensing unit 6 are designed to sense the deviation of the radial displacement of the rotating shaft and input it to the control system to adjust the radial balancing force, which is a supporting design for balancing the radial force.

[0048] Figure 4a and Figure 4bThe diagram below shows the structure of the radial bearing unit of the present invention. Referring to Figure 4, the first radial bearing unit 3 includes a first magnetic sleeve 301, a second magnetic shielding ring 302, a first anti-drop permanent magnet ring 303, a first coil 304, a first stator 305, a first anti-drop permanent magnet support 306, a first magnetic shielding retainer 307, and a second retaining ring 308. The first stator 305 is fixed to the left side of the first retainer 901 by bolts, with the bolt heads fully inserted into the countersunk holes of the first retainer 901. The right end face of the first stator 305 and the left end face of the first retainer 901 are in close contact. The first coils 304 are respectively sleeved on the stator columns. The first magnetic shielding retainer 307 is fixed to the lower inner side of the first stator 305 by the second retaining ring 308, located on the right side of the stator column. The first anti-drop permanent magnet support 306 is respectively fixed in the groove of the first magnetic shielding retainer 307. The first magnetic sleeve 301, the second magnetic isolation ring 302, and the first anti-drop permanent magnet ring 303 are fixed on the rotating shaft 5 from left to right, wherein the first magnetic sleeve 301 and the first anti-drop permanent magnet ring 303 are respectively opposite to the stator column and the first anti-drop permanent magnet support 306.

[0049] The second radial bearing unit 7 includes a second magnetic sleeve 701, a third magnetic shielding ring 702, a second anti-drop permanent magnet ring 703, a second coil 704, a second stator 705, a second anti-drop permanent magnet support 706, a second magnetic shielding retainer 707, and a third retaining ring 708. The second stator 705 is bolted to the second retainer 902, with the right end face of the second stator 705 in close contact with the left end face of the second retainer 902. The second coils 704 are respectively sleeved on the stator column. The second magnetic shielding retainer 707 is fixed to the lower inner side of the second stator 705 by the third retaining ring 708, located on the right side of the stator column. The second anti-drop permanent magnet support 706 is respectively fixed to the groove of the second magnetic shielding retainer 707. The second magnetic sleeve 701, the third magnetic isolation ring 702, and the second anti-drop permanent magnet ring 703 are fixed on the rotating shaft 5 from left to right, wherein the second magnetic sleeve 701 and the second anti-drop permanent magnet ring 703 are respectively opposite to the stator column and the second anti-drop permanent magnet support 706.

[0050] Figure 5 This is a schematic diagram of the axial balancing unit of the present invention, combined with... Figure 5Analysis reveals that the first axial balancing unit 2 includes a first sealing ring 201, a first retaining ring 202, a first axial thrust core 203, a first magnetic shielding ring 204, a first coil frame 205, a first axial electromagnetic coil 206, and a first balancing unit housing 207. The first balancing unit housing 207 is bolted to the first stator 305, with its right end face tightly against the left end face of the first stator 305. The first axial electromagnetic coil 206 is wound and fixed to the first coil frame 205, with the outer side of the first coil frame 205 tightly against the first balancing unit housing 207. The first retaining ring 202, the first axial thrust core 203, and the first magnetic shielding ring 204 are fitted onto the rotating shaft 5 from left to right, with the right end face of the first magnetic shielding ring 204 tightly against the left end face of the first magnetic sleeve 301. The first sealing ring 201 is also fitted onto the rotating shaft 5, located to the left of the first retaining ring 202.

[0051] The second axial balancing unit 8 includes a fourth magnetic shielding ring 801, a second axial thrust core 802, a fourth retaining ring 803, a fourth sealing ring 804, a second coil frame 805, a second axial electromagnetic coil 806, a second balancing unit housing 807, and a cover 808. The second balancing unit housing 807 is bolted to the second retainer 902, with its left end face tightly against the right end face of the second retainer 902. The second axial electromagnetic coil 806 is wound and fixed to the second coil frame 805, with the outer side of the second coil frame 805 tightly against the second balancing unit housing 807. The fourth magnetic shielding ring 801, the second axial thrust core 802, and the fourth retaining ring 803 are fitted onto the rotating shaft 5 from left to right. The left end face of the fourth magnetic shielding ring 801 is tightly against the right end face of the second anti-drop permanent magnet ring 703, and the fourth sealing ring 804 is located to the right of the fourth retaining ring 803.

[0052] The axial sensing unit 1 includes a first displacement sensor 101 and a first sensor holder 102. The first sensor holder 102 is fixed to the first balance unit housing 207 by bolts, with its right end face tightly attached to the left end face of the first balance unit housing 207. The first displacement sensor 101 is threaded onto the first sensor holder 102, and its cross-section is concentric with the cross-section of the rotating shaft 5.

[0053] The first radial sensing unit 4 includes a first end cap 401, a second sensor holder 402, a second displacement sensor 403, and a second sealing ring 404. The first end cap 401 is bolted to the first holder 901, with its left end face tightly against the right end face of the first holder 901. The second sensor holder 402 is bolted to the first end cap 401, with its left end face tightly against the right end face of the first end cap 401. The second displacement sensor 403 is threaded onto the second sensor holder 402. The second sealing ring 404 is fitted onto the rotating shaft 5, with its right end face tightly against the left end face of the second sensor holder 402.

[0054] The second radial sensing unit 6 includes a third displacement sensor 601, a third sensor holder 602, a second end cap 603, and a third sealing ring 604. The second end cap 603 is bolted to the second stator 705, with its right end face in close contact with the left end face of the second stator 705. The third sensor holder 602 is bolted to the second end cap 603, with its right end face in close contact with the left end face of the second end cap 603. The third displacement sensor 601 is threaded onto the third sensor holder 602. The third sealing ring 604 is fitted onto the rotating shaft 5, located on the right side of the third sensor holder 602, with its left end face in close contact with the right end face of the third sensor holder 602.

[0055] The bearing replaces the traditional thrust plate structure with a first axial balancing unit 2 and a second axial balancing unit 8. The first axial electromagnetic coil 206 and the second axial electromagnetic coil 806 are energized to generate magnetic fields. Under the magnetic field generated by the first axial electromagnetic coil 206, the first axial thrust core 203 generates an electromagnetic force in the left direction; under the magnetic field generated by the second axial electromagnetic coil 806, the second axial thrust core 802 generates an electromagnetic force in the right direction. The magnitudes of the two opposing electromagnetic forces are adjusted by the control system to achieve axial balance.

[0056] The bearings have added permanent magnet support portions to the first radial bearing unit 3 and the second radial bearing unit 7, respectively. The upper portion of the first anti-drop permanent magnet support 306, the upper portion of the second anti-drop permanent magnet support 706, the outer ring of the first anti-drop permanent magnet ring 303, and the outer ring of the second anti-drop permanent magnet ring 703 are N poles. The upper portion of the first anti-drop permanent magnet support 306, the outer ring of the first anti-drop permanent magnet ring 303, the upper portion of the second anti-drop permanent magnet support 706, and the outer ring of the second anti-drop permanent magnet ring 703 generate repulsive forces to provide radial support forces that balance the weight of the rotating shaft 5. When disassembly is required, simply remove the first displacement sensor 101 and first sensor holder 102 of the axial sensing unit 1, the second displacement sensor 403 and second sensor holder 402 of the first radial sensing unit 4, and the third displacement sensor 601 and third sensor holder 602 of the second radial sensing unit 6. The rotating shaft 5 and the parts fixed on it can then be pulled out from the left side as a whole. The parts include the first sealing ring 201, first retaining ring 202, first axial thrust core 203, and first magnetic shielding ring 204 of the first axial balancing unit 2; the first magnetic sleeve 301, second magnetic shielding ring 302, and first anti-drop permanent magnet ring 303 of the first radial bearing unit 3; the second sealing ring 404 of the first radial sensing unit 4; the third sealing ring 604 of the second radial sensing unit 6; the second magnetic sleeve 701, third magnetic shielding ring 702, and second anti-drop permanent magnet ring 703 of the second radial bearing unit 7; and the fourth magnetic shielding ring 801, second axial thrust core 802, and fourth retaining ring 803 of the second axial balancing unit 8.

[0057] The above design and installation method simplifies the bearing installation and disassembly steps; the entire shaft 5 and its fixed parts can be disassembled without disassembling the first radial bearing unit 3 and the second radial bearing unit 7, avoiding the complex adjustments required for reinstalling the first stator 305 and the first cage 901 of the first radial bearing unit 3 and the second stator 705 and the second cage 902 of the second radial bearing unit 7; removing the thrust plate structure can avoid shaft warping caused by temperature rise and deformation, improving the working accuracy of the bearing and extending its service life; the first anti-drop permanent magnet support 306 and the first anti-drop permanent magnet ring 303 added to the first radial bearing unit 3 generate supporting force, and the second anti-drop permanent magnet support 706 and the second anti-drop permanent magnet ring 703 added to the second radial bearing unit 7 generate supporting force to balance the bearing's own weight. When the electro-hydraulic support of the bearing fails, it can prevent the bearing from falling directly, thereby reducing shaft impact and wear, increasing bearing service life, and achieving the purpose of protecting the bearing.

[0058] The inner sides of both the first and second stators are provided with eight stator posts for connecting to the first or second coil.

[0059] Figure 6 This is a control diagram of a five-degree-of-freedom bearing system without a thrust plate according to the present invention, combined with... Figure 6 Analysis shows that the control parts of the first axial balancing unit 2 and the second axial balancing unit 8 of the bearing adopt a closed-loop negative feedback control strategy. When the shaft 5 undergoes axial displacement due to axial load, the displacement z detected by the first displacement sensor 101 is compared with the axial reference position z. ref The axial deviation displacement Δz obtained after comparison is input to the PID controller, and then output as a signal to power amplifier 1 and power amplifier 2 after digital-to-analog conversion. Power amplifier 1 outputs current Iz+iz to the first axial electromagnetic coil 206 of the first axial balancing unit 2, and power amplifier 2 outputs current Iz-iz to the second axial electromagnetic coil 806 of the second axial balancing unit 8. The first axial electromagnetic coil 206 is energized to generate a magnetic field, causing the first axial thrust core 203 of the first axial balancing unit 2 to generate a thrust in the left direction. The second axial electromagnetic coil 806 is energized to generate a magnetic field, causing the second axial thrust core 802 of the second axial balancing unit 8 to generate a thrust in the right direction. The first axial thrust core 203 and the second axial thrust core 802, which are fixed on the rotating shaft 5, drive the rotating shaft 5 to adjust its axial position, balance the external interference force, and keep the rotating shaft 5 at the set axial reference position z. ref .

[0060] The present invention also provides an installation process for a magnetic fluid dual suspension bearing, which includes the following steps:

[0061] S1. Assemble and install the radial bearing unit, which includes the following sub-steps:

[0062] S11. Wind the eight coils onto the stator columns of the two radial bearing units respectively.

[0063] S12. Fix the magnetic shielding cage to the bottom of the inner side of the stator using the retaining ring.

[0064] S13. Fix the anti-fall permanent magnet support body to the groove of the magnetic shielding retainer respectively.

[0065] S14. Stator bolts are installed on the left side of the left bracket and the left side of the right bracket of the cage, respectively, with the bolt heads entering the countersunk holes on the cage.

[0066] S2. Assemble and install the shaft, which includes the following sub-steps:

[0067] S21. Insert the sealing rings from the left and right sides of the shaft respectively, and fit them onto the left and right shoulders of the shaft respectively.

[0068] S22. Place the anti-drop permanent magnet ring, magnetic shielding ring, magnetic guide sleeve, magnetic shielding ring, and axial thrust iron core onto the rotating shaft in sequence, and fix them with the retaining ring and shaft shoulder. The right end face of the anti-drop permanent magnet ring should be in close contact with the left end face of the left side of the shaft shoulder, and the left end face of the axial thrust iron core should be in close contact with the right end face of the retaining ring.

[0069] S23. Pass the rotating shaft through the left stator, the cage, and the right stator from the left side, so that the magnetic sleeve and the anti-drop permanent magnet ring installed on the left side are opposite to the stator column and the anti-drop permanent magnet support body, respectively.

[0070] S24. Sequentially place the magnetic sleeve, magnetic shielding ring, anti-drop permanent magnet ring, magnetic shielding ring, and axial thrust iron core onto the rotating shaft, and secure them with the retaining ring and shaft shoulder. The left end face of the magnetic sleeve should be in close contact with the right end face of the right side of the shaft shoulder, and the right end face of the axial thrust iron core should be in close contact with the left end face of the retaining ring.

[0071] S3. Assemble and install the axial balancing unit, which includes the following sub-steps:

[0072] S31. Secure the left-side balance unit housing to the left-side stator with bolts, ensuring its right end face is flush with the left end face of the left-side stator. Secure the right-side balance unit housing to the second cage with bolts, ensuring its left end face is flush with the right end face of the second cage. Insert the bolt heads into the countersunk holes of the balance unit housing.

[0073] S32. The axial electromagnetic coil is wound and installed on the coil holder.

[0074] S33. Insert the axial electromagnetic coil and coil holder into the left and right side balance unit housings respectively, with their outer sides engaging with the inner side of the balance unit.

[0075] S34. Apply the sealing rings from the left and right sides of the shaft respectively.

[0076] S35. Fix the cover to the right side of the right balance unit housing with bolts, with its left end face tightly against the right end face of the right sealing ring, and the bolt head entering the countersunk hole of the cover.

[0077] S4. Install the axial sensing unit and the radial sensing unit, which includes the following sub-steps:

[0078] S41. Secure the left end cover to the first cage with bolts, ensuring its left end face is flush with the right end face of the first cage. Secure the right end cover to the second radial bearing unit with bolts, ensuring its right end cover is flush with the left end cover of the right stator. The bolt heads enter the countersunk holes of the end covers.

[0079] S42. Secure the sensor holder to the left side of the left balance unit housing, the right side of the left end cover, and the left side of the right end cover respectively using bolts, with the bolt heads entering the countersunk holes on the sensor holder.

[0080] S43. Install the displacement sensor onto each sensor holder via threads.

[0081] S5. The power unit is fixed to the right side of the right balance unit housing by bolts, with the bolt heads entering the countersunk holes on the right balance unit housing.

[0082] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A magnetic fluid dual-suspension bearing, characterized in that: It includes a rotating shaft, a cage, an axial sensing unit, a first axial balancing unit, a first radial bearing unit, a first radial sensing unit, a second radial sensing unit, a second radial bearing unit, a second axial balancing unit, and a power unit; the axial sensing unit, the first axial balancing unit, the first radial bearing unit, the first radial sensing unit, the second radial sensing unit, the second radial bearing unit, the second axial balancing unit, and the power unit are sequentially sleeved on the rotating shaft; the cage is disposed below the rotating shaft and is connected to the first radial bearing unit and the second radial bearing unit respectively; the cage includes a first cage and a second cage. The axial sensing unit is connected to the first end of the first balance unit housing of the first axial balance unit, and the second end of the first balance unit housing is connected to the first radial bearing unit. The first axial balancing unit includes a first retaining ring, a first axial thrust core, a first magnetic shielding ring, a first coil frame, a first axial electromagnetic coil, and a first balancing unit housing. The first axial thrust core is sleeved on the outside of the first end of the rotating shaft, the first coil frame is sleeved on the outside of the first axial thrust core, the first retaining ring is sleeved on the outside of the first end of the rotating shaft, and one side of the first retaining ring contacts the first end of the first axial thrust core. The first magnetic shielding ring is located on the outside of the first end of the rotating shaft and contacts the second end of the first axial thrust core. The first balancing unit housing is sleeved on the outside of the first coil frame, and there is a first electromagnetic coil mounting space for mounting the first axial electromagnetic coil between the first balancing unit housing and the first coil frame. The first axial electromagnetic coil is disposed within the first electromagnetic coil mounting space. The first radial bearing unit includes a first magnetic sleeve, a second magnetic isolation ring, a first anti-drop permanent magnet ring, a first coil, a first stator, a first anti-drop permanent magnet support, a first magnetic isolation retainer, and a second retaining ring. The first magnetic sleeve is sleeved on the outside of the first end of the rotating shaft, and the first end of the first magnetic sleeve contacts the first magnetic isolation ring, and the second end of the first magnetic sleeve contacts the second magnetic isolation ring. The second magnetic isolation ring is located on the outside of the first end of the rotating shaft. The first anti-drop permanent magnet ring is sleeved on the outside of the first end of the rotating shaft, and the first end of the first anti-drop permanent magnet ring contacts the second magnetic isolation ring. The second end of the first anti-drop permanent magnet ring contacts the first shoulder of the rotating shaft. A plurality of the first coils are arranged on the first magnetic sleeve. The first coil is fixedly connected to the stator column of the first stator on the outside of the magnetic sleeve. The first anti-fall permanent magnet support is sleeved on the outside of the first anti-fall permanent magnet ring. The first anti-fall permanent magnet support is fixedly connected to the first magnetic isolation retainer. The first magnetic isolation retainer is sleeved on the outside of the first anti-fall permanent magnet ring. The first stator is sleeved on the outside of the first coil, the first anti-fall permanent magnet support and the first magnetic isolation retainer. The first end of the first stator is connected to the first balance unit shell. The second end of the first stator is connected to the first retainer. The first stator is provided with a plurality of stator columns for connecting the first coil. The first magnetic isolation retainer is connected to the first stator through the second retaining ring. The second radial bearing unit includes a second magnetic sleeve, a third magnetic isolation ring, a second anti-drop permanent magnet ring, a second coil, a second stator, a second anti-drop permanent magnet support, a second magnetic isolation retainer, and a third retaining ring. The second magnetic sleeve is sleeved on the outside of the second end of the rotating shaft, and the first end of the second magnetic sleeve contacts the second shoulder of the rotating shaft. The second end of the second magnetic sleeve contacts the third magnetic isolation ring. Both the third magnetic isolation ring and the second anti-drop permanent magnet ring are located on the outside of the second end of the rotating shaft, and the first end of the second anti-drop permanent magnet ring contacts the third magnetic isolation ring. The second end of the second anti-drop permanent magnet ring contacts the second axial balance unit. Multiple second coils are disposed on the outside of the second magnetic sleeve, and the second coils are fixedly connected to the stator column inside the second stator. The second anti-drop permanent magnet support is sleeved on the outside of the second anti-drop permanent magnet ring, and the second anti-drop permanent magnet support is fixedly connected to the second magnetic isolation retainer. The second magnetic isolation retainer is sleeved on the outside of the second anti-drop permanent magnet ring. The second stator is sleeved on the outside of the second coil, the second anti-drop permanent magnet support and the second magnetic isolation retainer. The first end of the second stator is connected to the second end cover of the second radial sensing unit, and the second end of the second stator is connected to the second retainer. The second axial balancing unit includes a fourth magnetic isolation ring, a second axial thrust core, a fourth retaining ring, a fourth sealing ring, a second coil frame, a second axial electromagnetic coil, a second balancing unit housing, and a cover. The fourth magnetic isolation ring, the second axial thrust core, and the fourth retaining ring are all sleeved on the outside of the second end of the rotating shaft. The fourth magnetic isolation ring and the fourth retaining ring are respectively disposed at both ends of the second axial thrust core, and the fourth magnetic isolation ring is in contact with the second end of the second anti-drop permanent magnet ring. The second coil frame is sleeved on the outside of the second axial thrust core and the fourth retaining ring. The second balancing unit housing is sleeved on the outside of the second coil frame, and there is a second electromagnetic coil mounting space between the second balancing unit housing and the second coil frame. The second axial electromagnetic coil is disposed within the second electromagnetic coil mounting space.

2. The magnetic fluid dual suspension bearing according to claim 1, characterized in that: The axial sensing unit includes a first displacement sensor and a first sensor holder. The first displacement sensor is disposed at the center of the first surface of the first sensor holder, and the detection point of the first displacement sensor is aligned with the end face of the first end of the rotating shaft. The second end of the first sensor holder is connected to the housing of the first balance unit.

3. The magnetic fluid dual suspension bearing according to claim 2, characterized in that: The first radial sensing unit includes a first end cap, a second sensor holder, and a second displacement sensor. The first side of the first end cap is connected to one end of the first holder, and the second sensor holder is provided on the second side of the first end cap. Four second displacement sensors are evenly distributed on the second sensor holder, and the detection points of the second displacement sensors are aligned with the direction of rotation.

4. The magnetic fluid dual suspension bearing according to claim 3, characterized in that: The second radial sensing unit includes a third displacement sensor, a third sensor holder, and a second end cap. The second side of the second end cap is connected to the first end of the second stator. The first side of the second end cap is provided with a third sensor holder. Four third displacement sensors are evenly arranged on the third sensor holder. The detection points of the third displacement sensors are aligned with the direction of the rotation axis.

5. The magnetic fluid dual suspension bearing according to claim 4, characterized in that: It also includes a first sealing ring, a second sealing ring, a third sealing ring, and a fourth sealing ring. The first sealing ring is disposed at the connection between the first coil frame and the rotating shaft, and the first end of the first sealing ring contacts the first end of the first sensor holder. The second sealing ring is disposed at the connection between the first end cover and the rotating shaft to prevent leakage of internal oil. The third sealing ring is disposed at the connection between the second end cover and the rotating shaft to prevent leakage of internal oil. The fourth sealing ring is disposed at the connection between the second coil frame and the rotating shaft, and the first end of the fourth sealing ring contacts the first end of the cover.

6. The magnetic fluid dual suspension bearing according to claim 1, characterized in that: The retainer is also provided with a retaining plate. Both the first retainer and the second retainer are disposed above the retaining plate and are perpendicular to the retaining plate.

7. The magnetic fluid dual suspension bearing according to claim 1, characterized in that: The power unit is hinged to the second end of the rotating shaft and drives the rotating shaft to rotate.

8. The magnetic fluid double suspension bearing according to claim 1, characterized in that: In operation, the first retaining ring, the first axial thrust iron core, the first magnetic isolation ring, the first magnetic guiding sleeve, the second magnetic isolation ring, the first anti-drop permanent magnet ring, the second magnetic guiding sleeve, the third magnetic isolation ring, the second anti-drop permanent magnet ring, the fourth magnetic isolation ring, the second axial thrust iron core, and the fourth retaining ring rotate with the rotation of the shaft.

9. A method for installing the magnetic fluid double suspension bearing as described in claim 1, characterized in that: It includes the following installation steps: S1. Assemble and install the radial bearing unit; S2. Assemble and install the shaft; S3. Assemble and install the axial balancing unit; S4. Install the axial sensing unit and the radial sensing unit; S5. The power unit is fixed to the right side of the right balance unit housing by bolts, with the bolt heads entering the countersunk holes on the right balance unit housing.

10. A control system for the magnetic fluid double suspension bearing according to any one of claims 1-8, characterized in that: The axial balancing unit control section adopts a closed-loop negative feedback control strategy. The control process includes the following steps: S1. Set the axial reference position of the shaft, which meets the axial position required for the shaft to operate normally; S2. Apply an axial load to the shaft to cause axial displacement of the shaft; S3. The axial displacement sensor detects the change in the axial position of the rotating shaft and obtains the axial deviation displacement data by comparing it with the set axial reference position; S4. The axial displacement sensor inputs the obtained axial deviation displacement data into the PID controller; S5, then the output signal is converted from digital to analog and sent to two power amplifiers; S6, the power amplifier outputs current to the axial electromagnetic coils of the first axial balancing unit and the axial electromagnetic coils of the second axial balancing unit, respectively; S7. When the coil is energized, it generates a magnetic field that causes the first axial balancing unit and the second axial balancing unit to generate forces in the left and right directions, respectively. S8. The axial position of the rotating shaft is adjusted by two axial thrust iron cores fixed on the rotating shaft; S9: Closed-loop negative feedback control achieves dynamic balance, and the shaft is maintained at the axial reference position.

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