Rolling bearing active magnetic control targeted lubrication structure and lubrication method based on magnetic fluid

Abstract

The invention relates to the technical field of bearing lubrication, in particular to a rolling bearing active magnetic control targeted lubrication structure based on magnetic fluid and a lubrication method. The magnetic fluid lubricant is captured, agglomerated and guided to migrate to a lubrication target area by constructing a variable gradient combined magnetic field source and regulating and controlling the magnitude and the direction of the magnetic field force. The active lubricating method comprises the steps that firstly, liquid drops of a magnetofluid lubricant enter a rolling bearing cavity from a spraying inlet and then are diffused, and then the liquid drops are captured by an external magnetic field source and gradually agglomerate; and then a gradient magnetic field from the injection inlet to the target lubrication area is formed by changing magnetic field source regulation and control parameters, and the magnetic fluid is guided to overcome the effects of flow potential, pressure gradient potential and resistance potential and migrate to the target lubrication area in a targeted mode. The problems that a traditional lubricating medium is difficult to enter a bearing contact area and the circumferential direction distribution is uneven are fundamentally solved, the lubricating efficiency of the ultra-high-speed bearing is improved, and the effects of quantitative, accurate and active lubrication and real-time regulation and control are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing lubrication, and in particular to a magnetic fluid-based active magnetically controlled targeted lubrication structure and a lubrication method for a rolling bearing. Background Art

[0002] The main purpose of bearing lubrication is to reduce friction and wear, cool and dissipate heat, extend service life, prevent corrosion and pollution, and reduce operating noise. Common bearing lubrication methods include manual oil lubrication, drip oil automatic lubrication, oil ring lubrication technology, oil rope guided lubrication, oil pad capillary lubrication, oil bath immersion lubrication, splash lubrication, spray lubrication technology and pressure oil supply lubrication system.

[0003] Traditional jet lubrication technology faces two key challenges: how to inject high-speed, high-pressure oil and gas into the bearing raceways to achieve stable and continuous oil supply; and how to ensure that the injected lubricant smoothly enters the ball-raceway contact area to form a continuous and reliable lubricating film. It should be noted that sliding bearings do not have a contact area, so these two key issues are impossible to address.

[0004] Therefore, to address the problems that arise after lubricating oil is injected into the bearing raceways, as the bearing's maximum speed continues to increase, the coupling of the high-speed revolution, spin, and gyroscopic motion of the rolling elements causes intense turbulence and vortex flow within the bearing cavity. This creates a high-speed, high-pressure air vortex ("air barrier") around the rolling elements, increasing resistance to oil and air flow within the bearing cavity. This prevents the lubricant from flowing directly into the raceways, resulting in poor bearing lubrication, increased frictional heat, and bearing failure, hindering the improvement of jet lubrication efficiency. To this end, bearing manufacturer SKF abandoned traditional oil supply methods and proposed a solution for jet lubrication by drilling holes in the bearing rings. This solution, while somewhat circumventing the effects of the high-pressure air barrier, significantly alters the bearing structure, causing stress concentration in the rings, severely reducing support stiffness and service life, making it difficult to implement on a large scale. Japan's NTN Corporation, building on the traditional side-injection method, extended the oil and air nozzle to bypass the high-pressure air barrier, largely avoiding the effects of the high-pressure air barrier.

[0005] The most crucial challenge remains ensuring that the lubricating medium, after passing through the high-pressure air barrier, can evenly and adequately enter the ball-raceway contact zone to form an effective lubricating film (the second key issue facing jet lubrication technology). Limited by the rotating structure of the bearing rings and balls, the extended nozzle cannot directly reach the raceway contact zone. The lubricating oil and gas are therefore only sprayed into the vicinity of the bearing contact zone. There, entrained by the high-speed, turbulent airflow and driven by the bearing assembly, they further migrate, diffuse, and aggregate. The high-speed orbital motion of the bearing severely hinders the axial expansion of the lubricating medium, causing the majority of the lubricating oil and gas to flow in the direction of the rings' orbital motion. The small amount of lubricating medium that does reach the raceway is thrown into non-contact areas due to centrifugal loads, preventing it from effectively participating in lubrication. This results in reduced lubricant utilization and hinders efficient bearing lubrication.

[0006] Furthermore, the diffusion of the lubricant within the bearing cavity is affected by gravity and centrifugal loads, resulting in significantly higher oil content in the lower bearing cavity than in the upper and left and right bearing cavities. The outer ring raceway also contains more oil than the inner ring raceway. This significant variation in lubricant content distribution across the bearing cavity results in dry friction in some key load-bearing areas due to low oil content, leading to severe wear and temperature rise. Excessive lubricant accumulation in the lower cavity also leads to increased churning losses and excessive temperature rise, which is also detrimental to the stable operation of the bearing.

[0007] As an intelligent nano-lubrication technology, magnetic fluid has become one of the reliable materials for solving complex engineering problems such as sliding bearing lubrication and precision instrument sealing due to its wide load range, high controllability, self-sealing, self-recovery and long life. However, due to the contact area size of rolling bearings (submicron level 10 -7 ~10 -8 m) is extremely small, and the internal structure of rolling bearings is complex. Cross-scale (millimeter to submicron) magnetic guidance and active flow field control technology is difficult. Specifically, since the bearing lubricant in the bearing cavity is subject to complex thermal coupling effects such as flow field force, concentration field, pressure field, and temperature field, it is difficult to capture and control it. In addition, the size of the bearing is generally decimeter or millimeter. -2 or 10 -3 m, and the contact area is generally 10 -7 m or 10 -8 The size of the bearing is around 1000 m, making cross-dimensional control difficult. This is equivalent to stitching the cell wall of a single cell in the human body using the naked eye and hands. Therefore, it has not yet been widely used in bearing jet lubrication.

[0008] The patent, CN118208498A, titled "A Magnetic Fluid Precision Localized Lubrication Bearing Device and Its Processing Technology," involves installing the rolling elements in a cage. The bearing inner ring, the cage containing the rolling elements, and the outer ring are then assembled. Magnetic fluid lubricant is then injected and oil retaining rings are installed on both sides. An annular magnet is then embedded in the bearing seat, and two layers of annular washers are installed into the bearing seat. Finally, the assembled bearing is assembled into the bearing seat embedded with the annular magnet. To adjust the magnetic field, the effect of the annular magnet on the magnetic fluid lubricant can be adjusted by adding or removing non-magnetic and magnetically conductive annular washers, thereby altering the effect of the annular magnet on the magnetic fluid lubricant. The magnetic fluid lubricant has the property of being able to remain in the lubricated area under the influence of an applied magnetic field. This property allows the magnetic fluid to offset the effects of gravity and centripetal force, achieving more stable and efficient lubrication. When the annular magnet and magnetic fluid lubricant work together, the magnetic field of the annular magnet causes the magnetic fluid to form an oil film on the surface of the rolling elements. Through the action of the magnetic field, the magnetic fluid accurately fills the lubricated surface, achieving continuous lubrication and preventing dry friction.

[0009] The magnetic fluid lubrication mentioned in this patent is mainly oil lubrication, not jet lubrication. In addition, the magnetic field of this patent is realized by permanent magnets, which is different from the electromagnetic coil used in this application, that is, electromagnetism. The most important thing is that the magnetic field of this invention cannot be adjusted in real time. After the permanent magnet is fixed, the size and direction of its magnetic field are fixed. In addition, this invention only fixes the lubricating medium around the rolling element through the magnetic field, and it is not the contact area that needs lubrication. It cannot provide quantitative and precise lubrication, nor is it active lubrication. It only solves the problem of dry friction. However, the lubricating oil will be excessive, and the stirring of the oil will generate serious heat. Moreover, after the bearing runs at high speed, the lubricating oil deviates from the area to be lubricated due to the combined action of various loads, and the lubrication effect is extremely poor. Another patent, publication number CN110594288B, titled "A Magnetic Control Flexible Pad Thrust Sliding Bearing Based on Nano-Magnetic Fluid," uses a gradient magnetic field to fix the pads, causing the oil film formed by the nano-magnetic fluid to form flexible pads with a certain inclination angle. This forms a load-bearing oil wedge with the surface of the thrust plate, enabling hydrodynamic lubrication at lower relative sliding speeds, reducing friction and wear on the thrust surface while also providing cooling and vibration absorption. Furthermore, the inclination angle of the flexible pads can vary with the axial load of the rotating shaft, reducing damage to the bearings from impact vibration and ensuring smooth rotation of the shaft, making it suitable for a variety of operating conditions.

[0010] However, this patent is a structural design of a sliding bearing. The function of the gradient magnetic field it adopts is to generate a lubricating oil film, not to regulate the magnetic field. This is related to the working principle of the sliding bearing. If the oil film is not formed, the stator and rotor of the sliding bearing cannot be separated, and the sliding bearing cannot work. The lubricating oil film of the sliding bearing is formed for support, and the lubrication of the rolling bearing is used to reduce friction and heat dissipation. Therefore, the lubrication control of sliding bearings and rolling bearings are two completely different technologies.

[0011] The patent also mentions that "nano-magnetic liquid is a new type of functional material. It is a stable colloidal solution formed by coating nano-scale magnetic particles with a surfactant molecular layer and uniformly dispersing them in a base carrier liquid. The nano-scale magnetic particles uniformly dispersed in the base carrier liquid will be affected by the magnetic force in an external magnetic field, so the nano-magnetic liquid can also be controlled by the magnetic field. The movement, positioning and deformation of the nano-magnetic liquid can be controlled by an external magnetic field. Based on the special properties of the nano-magnetic liquid, the nano-magnetic liquid has good lubrication effect and load-bearing capacity as a lubricant." However, these two prior arts do not involve jet lubrication, and cannot achieve magnetic fluid lubrication for rolling bearings. Summary of the Invention

[0012] In order to comprehensively solve the above problems, the present invention aims to design an active magnetic control targeted lubrication structure and lubrication method for rolling bearings based on magnetic fluid. This application is the first time that magnetic fluid lubrication is applied to rolling bearings based on jet lubrication. Through the active regulation method of magnetic control, circumferential uniform distribution and appropriate lubrication in the contact area are achieved, further realizing precise lubrication of rolling bearings, avoiding the problems of excessive lubricant causing oil stirring and heat generation or insufficient lubricant turning into boundary lubrication, resulting in increased friction and severe heat generation.

[0013] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides an active magnetically controlled targeted lubrication structure for rolling bearings based on magnetic fluid, including a combined magnetic field source, which includes an external uniform magnetic field source and an internal micromagnetic field source. The external uniform magnetic field source provides a large magnetic field intensity, and the internal micromagnetic field source provides a gradient magnetic field. The internal micromagnetic field source regulates the magnetic volume force exerted on the magnetic fluid lubricant in the rolling bearing cavity.

[0014] Preferably, the external uniform magnetic field source is composed of two sets of Helmholtz coils located in the same plane and intersecting perpendicularly. The two sets of coils generate uniform magnetic fields in the X direction and the Y direction respectively. After the two uniform magnetic fields are located in the same plane and superimposed vectorially, a uniform magnetic field in any direction in the same plane is formed. By changing the current magnitude and direction of the two groups of Helmholtz coils respectively, the direction and magnitude of the uniform magnetic field can be adjusted.

[0015] Preferably, the internal gradient magnetic field source is composed of a group of micro-conductors formed by two conductors with opposite currents, and a micro-conductor array is formed by multiple groups of micro-conductors to provide a gradient magnetic field; The magnitude and direction of the current flowing into each group of microconductors can be adjusted in real time and individually, thereby forming an internal gradient magnetic field source with variable magnitude and direction.

[0016] The second aspect of the present invention provides an active lubrication method for a rolling bearing active magnetically controlled targeted lubrication structure based on magnetic fluid. First, droplets of magnetic fluid lubricant enter the rolling bearing cavity from the injection inlet and diffuse, and then are captured by the combined magnetic field source and gradually agglomerated. According to the lubrication requirements of the in-service bearing, the parameters of the combined magnetic field source are controlled in real time to form a gradient magnetic field from the injection inlet to the target lubrication area. By changing the agglomeration concentration, migration path, and migration rate of the magnetic fluid lubricant, the magnetic fluid is guided to overcome the effects of flow potential, pressure gradient potential, and resistance potential, and migrate to the target lubrication area in a targeted manner, thereby ultimately achieving timed and quantitative refined lubrication control of the bearing.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The magnetically controlled targeted lubrication method for rolling bearings of the present invention is an active lubrication method that can adjust the agglomeration concentration, migration path, migration rate, etc. of the magnetic fluid lubricant in real time according to the lubrication needs of the in-service bearings, thereby realizing timed and quantitative refined lubrication control of the bearings, and fundamentally solving the problem that traditional lubricating media are difficult to enter the contact area and are unevenly distributed in the circumferential direction.

[0018] Quantification refers to the amount of lubricant required in the lubrication area (contact zone). Through regulation, a fixed amount of lubricant can be supplied to the lubricated area with very small errors. Furthermore, the demand for each area (at different locations within the bearing) varies, and the regulation of the present invention also varies the supply amount. Precision has three meanings: first, the lubrication area is precisely determined down to the micron level of the contact area; second, the precise lubrication location enables precise axial point lubrication; and third, the precise amount of lubrication, delivering the exact amount required. Active lubrication means that existing lubrication methods are passive, while the present invention achieves demand-based active lubrication through real-time magnetic field regulation based on actual operating conditions. Real-time regulation refers to the real-time regulation of lubrication based on actual lubrication needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0020] In the attached figure: Figure 1 Schematic diagram of traditional jet lubrication; Figure 2 Schematic diagram of targeted lubrication; Figure 3 Schematic diagram of variable gradient magnetic field; Figure 4 Schematic diagram of external uniform magnetic field source; Figure 5 Schematic diagram of the internal gradient magnetic field source; Figure 6 It is a schematic diagram of the principle of the present invention. DETAILED DESCRIPTION

[0021] The following combination Figures 1-6 The preferred embodiments of the present invention are described herein. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] like Figure 1 This is a schematic diagram of traditional jet lubrication. In order to solve the problems existing in the prior art, the following embodiments are proposed.

[0023] Example 1: like Figure 1 , currently the magnetic fluid in the bearing cavity (mm level 10 -3 m) and contact area (submicron level 10 -7 ~10 -8 The migration between the target area and the magnetic source is a cross-scale movement, and its targeted behaviors such as capture, agglomeration and migration are extremely complex. At the same time, the magnetic field strength and gradient decrease with increasing distance. If the position and size of the magnetic field source are not set reasonably, it is easy to cause a large number of magnetic fluid oil droplets to gather between the target area and the magnetic source, reducing the targeting efficiency. This undoubtedly greatly increases the difficulty of fine micro-control design of the magnetic field source. In addition, most of the current magnetic sources are single magnetic sources. The static magnetic field force cannot provide flexible magnetic force direction and cannot guide the magnetic fluid oil droplets in any direction. The magnetic fluid oil droplets are subjected to complex forces in the bearing cavity. If the magnetic field strength and direction do not change, the captured magnetic fluid oil droplets will most likely stop migrating before reaching the target area due to force balance, making it difficult to accurately control the dynamic behavior of magnetic fluid targeting in ultra-high-speed bearing cavities.

[0024] Therefore, this application designs a magnetic field source with real-time adjustable magnetic field force size and direction to achieve precise control of targeted dynamic behaviors such as capture, agglomeration, and migration of magnetic fluid oil droplets in ultra-high-speed bearing cavities, thereby solving the problem of difficulty for the lubricating medium to enter the contact area and uneven circumferential distribution.

[0025] In order to achieve the above technical effects, Figure 6This application proposes an active magnetically controlled targeted lubrication structure for rolling bearings based on magnetic fluid. For active lubrication, the traditional rolling bearing lubricating medium is modulated into a magnetic fluid lubricant, and a combined magnetic field source with a variable gradient is constructed. The agglomeration concentration, migration path, migration rate, etc. of the magnetic fluid lubricant are adjusted in real time according to the lubrication needs of the in-service bearings, thereby realizing timed and quantitative refined lubrication control of the bearings, and fundamentally solving the problem that traditional lubricating media are difficult to enter the contact area and are unevenly distributed in the circumferential direction.

[0026] The combined magnetic field source includes an external uniform magnetic field source and an internal micro-magnetic field source. The external uniform magnetic field source provides a high magnetic field intensity, while the internal micro-magnetic field source provides a gradient magnetic field. The internal micro-magnetic field source regulates the magnetic volume force acting on the magnetic fluid lubricant in the rolling bearing cavity. The external uniform magnetic field source creates the main magnetic field intensity system, while the internal micro-magnetic field source creates the main magnetic field gradient system.

[0027] The main magnetic field strength system realizes coarse adjustment, and the main magnetic field gradient system realizes fine adjustment. The external uniform magnetic field source can ensure the large magnetic field direction and strength, and adjust the macroscopic flow of magnetic fluid to meet the adjustment requirements, while the internal micromagnetic field source is fine-tuned, and precise control is carried out through the gradient magnetic field.

[0028] Because the rolling bearing cavity is at the millimeter level, a large magnetic field is required for large-direction adjustment to guide it toward the contact area, while the contact area is at the sub-micron level and requires a gradient magnetic field for fine-tuning.

[0029] Therefore, this application uses two independent systems to make up for the shortcomings of the external uniform magnetic field source and the internal micromagnetic field source on the one hand, and on the other hand, it eliminates the unified relationship between the magnetic field intensity and the magnetic field gradient under a single system, thereby further adjusting the force application method.

[0030] The external uniform magnetic field source consists of two sets of Helmholtz coils located in the same plane and intersecting perpendicularly. The two sets of coils generate uniform magnetic fields in the X and Y directions respectively. The two uniform magnetic fields are located in the same plane and superimposed vectorially to form a uniform magnetic field in any direction within the same plane. By changing the current magnitude and direction of the two groups of Helmholtz coils respectively, the direction and magnitude of the uniform magnetic field can be adjusted.

[0031] The internal gradient magnetic field source is composed of a group of micro-conductors formed by two conductors with opposite currents, and then multiple groups of micro-conductors are used to form a micro-conductor array to provide a gradient magnetic field; The magnitude and direction of the current flowing into each group of microconductors can be adjusted in real time and individually, thereby forming an internal gradient magnetic field source with variable magnitude and direction.

[0032] Magnetic fluid lubricants are existing substances and can be used as existing products. They can also be prepared using the following existing method: "Research on the Preparation of Nanomagnetic Granular Magnetic Fluid Lubricants" (Tang Baolin, Liu Shujin, Yang Zhiyi, 2023 National Powder Equipment, Technology, and Product Information Exchange Conference), which has the same effect.

[0033] Magnetic fluid lubricant is a colloidal suspension liquid composed of a mixture of surfactants, base carrier liquid and nano-magnetic particles. When there is no external magnetic field, it does not exhibit magnetism, presents a free-flowing liquid state, and has good lubrication function; when there is an external magnetic field, it exhibits superparamagnetism and can be stably controlled by the magnetic field.

[0034] Common magnetic particles currently used include Fe₃O₄, Ni-Fe, Co, and ε-Fe₃N nanoparticles. Carrier fluids primarily include kerosene, hydrocarbons, water, organic solvents, and magnetic fluids. The same type of magnetic particle exhibits varying lubrication properties when incorporated into different carrier fluids. Currently, Fe₃O₄ nanoparticles are the most common type of magnetic nanoparticles.

[0035] The saturation magnetization of Fe₃O₄ nanoparticles is relatively low, reaching a maximum of approximately 850 GS. However, they exhibit excellent stability and exhibit no magnetic degradation. The chemical coprecipitation method is simple to prepare, requires minimal equipment, and can leverage factors influencing particle size distribution to control the nanoparticle size, thereby meeting the required magnetic nanoparticle size for stable magnetic fluid lubricants. We used chemical coprecipitation to prepare the particles and selected an appropriate surfactant based on the particle size and carrier liquid to produce nanoparticles of the desired size. These nanoparticles were then dried and dispersed in an organic carrier liquid to create a magnetic fluid lubricant with excellent stability.

[0036] The surfactant was dispersant A-218.

[0037] The specific preparation method is as follows: (1) Reagents and instruments Chemical reagents: analytical grade ferric sulfate, analytical grade ferrous sulfate, sodium hydroxide, hydrochloric acid (36%~38%), anhydrous ethanol, surfactant, distilled water, 46# turbine oil Main instruments: constant temperature water bath, stirrer, PHS-2 pH meter, JEM-200CX transmission microscope, drying oven, M200 friction and wear testing machine (2) Preparation of Fe3O4 nanoparticle powder Ferric sulfate and ferrous sulfate, respectively, were added to distilled water to prepare solutions A (0.5 mol / L) and B (0.5 mol / L). Solutions A and B were mixed in a beaker and heated in a water bath. A 133.3 × 6 mol / L NaOH solution was added, stirred, and allowed to react for 20 minutes while maintaining the temperature at 70°C. A surfactant was then added, and the reaction was allowed to continue for a specified period of time. Finally, HCl solution was added to raise the pH to 5.5, producing a precipitate. The precipitate was then washed, filtered, and dried in a 100°C oven for 24 hours to produce Fe₃O₄ nanoparticle powder.

[0038] (3) Preparation of magnetic fluid lubricant The Fe3O4 nanoparticle powder prepared above was dispersed in a base carrier liquid (ordinary lubricating oil 46# turbine oil), and an appropriate amount of dispersant was added. After stirring and separation by a centrifugal separator, the particles that failed to be stably dispersed were removed to prepare a Fe3O4 nanoparticle magnetic fluid lubricant with good stability.

[0039] in, Figure 2 Schematic diagram of targeted lubrication; Figure 3 Schematic diagram of variable gradient magnetic field; Figure 4 Schematic diagram of external uniform magnetic field source; Figure 5 Schematic diagram of the internal gradient magnetic field source.

[0040] Example 2: An active lubrication method for a rolling bearing active magnetically controlled targeted lubrication structure based on magnetic fluid. First, droplets of magnetic fluid lubricant enter the rolling bearing cavity from the injection inlet and diffuse, and then are captured by a combined magnetic field source and gradually agglomerated. According to the lubrication requirements of the in-service bearing, the parameters of the combined magnetic field source are controlled in real time to form a gradient magnetic field from the injection inlet to the target lubrication area. By changing the agglomeration concentration, migration path, and migration rate of the magnetic fluid lubricant, the magnetic fluid is guided to overcome the effects of flow potential, pressure gradient potential, and resistance potential, and migrate to the target lubrication area, ultimately achieving timed and quantitative refined lubrication control of the bearing.

[0041] The traditional lubrication method does not intervene once the lubricating oil enters the bearing cavity. The lubrication accuracy is at the millimeter level, which is passive lubrication.

[0042] The present invention actively regulates and guides lubricating oil after it enters the bearing cavity, directing it to the bearing contact zone. This lubrication accuracy is at the micron or even submicron level, and it is proactive. This significantly reduces bearing temperature rise, keeping aircraft engine bearing temperatures within normal operating ranges over the long term. Lubricating oil is supplied on demand, resulting in significant economic benefits and avoiding the generation of heat from excessive lubricating oil. Furthermore, the proactive regulation of the present invention ensures uniform distribution of lubricating oil around the bearing circumference, ensuring a uniform temperature rise at all points.

[0043] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. An active magnetically controlled targeted lubrication structure for rolling bearings based on magnetic fluid, characterized in that: It includes a combined magnetic field source, which includes an external uniform magnetic field source and an internal micro magnetic field source. The external uniform magnetic field source provides a large magnetic field intensity, and the internal micro magnetic field source provides a gradient magnetic field. The internal micro magnetic field source regulates the magnetic volume force exerted on the magnetic fluid lubricant in the rolling bearing cavity.

2. The active magnetically controlled targeted lubrication structure for rolling bearings based on magnetic fluid according to claim 1, characterized in that: The external uniform magnetic field source consists of two sets of Helmholtz coils located in the same plane and intersecting perpendicularly. The two sets of coils generate uniform magnetic fields in the X and Y directions respectively. The two uniform magnetic fields are located in the same plane and superimposed vectorially to form a uniform magnetic field in any direction within the same plane. By changing the current magnitude and direction of the two groups of Helmholtz coils respectively, the direction and magnitude of the uniform magnetic field can be adjusted.

3. The active magnetically controlled targeted lubrication structure for rolling bearings based on magnetic fluid according to claim 2, characterized in that: The internal gradient magnetic field source is composed of a group of micro-conductors formed by two conductors with opposite currents, and then multiple groups of micro-conductors are used to form a micro-conductor array to provide a gradient magnetic field; The magnitude and direction of the current flowing into each group of microconductors can be adjusted in real time and individually, thereby forming an internal gradient magnetic field source with variable magnitude and direction.

4. The active lubrication method of the rolling bearing active magnetically controlled targeted lubrication structure based on magnetic fluid according to any one of claims 1 to 3, characterized in that: First, the droplets of magnetic fluid lubricant enter the rolling bearing cavity from the injection inlet and diffuse, and then are captured by the combined magnetic field source and gradually agglomerated; according to the lubrication requirements of the in-service bearing, the parameters of the combined magnetic field source are adjusted in real time to form a gradient magnetic field from the injection inlet to the target lubrication area. By changing the agglomeration concentration, migration path, and migration rate of the magnetic fluid lubricant, the magnetic fluid is guided to overcome the effects of flow potential, pressure gradient potential, and resistance potential, and migrate to the target lubrication area, ultimately achieving timed and quantitative refined lubrication control of the bearing.

Images