Piezoelectric ceramic bearing

Abstract

The utility model relates to the field of mechanical engineering, in particular to a piezoelectric ceramic bearing made of piezoelectric ceramic materials, which comprises a bearing outer ring, a bearing inner ring, a ball and a retainer, the ball and the retainer are fixed between the bearing outer ring and the bearing inner ring, both the bearing outer ring and the bearing inner ring are made of piezoelectric ceramic materials, and the piezoelectric ceramic materials are of multi-layer composite structures. The balls and the retainer are tightly attached to the second conducting layer of the bearing outer ring and the third conducting layer of the bearing inner ring respectively, the first conducting layer of the bearing outer ring and the fourth conducting layer of the bearing inner ring are fixed to external equipment respectively, the first conducting layer and the second conducting layer are connected through a metal shifting piece, and the metal shifting piece is connected to an external circuit. A self-induction function is introduced into the bearing, so that the running state of the bearing can be monitored and controlled in real time, the working precision of a bearing system is improved, the service life of equipment is prolonged, the anti-interference capability of the bearing system is enhanced, stable running of high-precision equipment is ensured, and the production efficiency and the reliability of a production line are improved.

Description

Technical Field

[0001] The utility model relates to the field of mechanical engineering, in particular to a piezoelectric ceramic bearing made of piezoelectric ceramic material, which is used in high-precision rotating mechanical equipment. Background Art

[0002] As a key component in mechanical equipment to reduce friction and support rotating or moving parts, traditional bearings are widely used in various mechanical systems. They are mainly divided into two categories: rolling bearings and sliding bearings. Rolling bearings reduce friction by rolling rolling elements (such as balls or rollers) between inner and outer rings. They are commonly used in automobiles, machine tools, household appliances and other equipment. Sliding bearings reduce friction by forming an oil film between the sliding surfaces with lubricants. They are suitable for occasions with large loads and low-speed rotation, such as large mechanical equipment and heavy vehicles. However, there are still some problems and disadvantages in some special applications. First, friction and wear are the main problems faced by traditional bearings. Rolling bearings are prone to friction and wear under high-speed rotation or heavy loads, resulting in shortened life and frequent maintenance. Although sliding bearings reduce friction through lubricants, they are prone to direct contact wear in the absence of lubrication or insufficient lubrication. Secondly, the manufacturing accuracy of traditional bearings is limited, and it is difficult to meet the needs of ultra-high-precision mechanical equipment, such as nano-level processing equipment and high-precision positioning systems. The lack of accuracy limits their application in some high-demand occasions. Finally, traditional bearings have a single function. Their main function is to reduce friction and support rotating or moving parts. They are unable to realize intelligent functions such as self-sensing and self-driving. The lack of this function limits the application of traditional bearings in intelligent manufacturing and automation systems.

[0003] The main reasons for these problems and shortcomings include material limitations, single structural design, lubrication dependence and manufacturing precision limitations. Traditional bearings are mainly made of metal and plastic, which have limited performance in high temperature, high pressure or corrosive environments and are difficult to meet special application requirements. The design of traditional bearings mainly focuses on mechanical support and friction reduction, and fails to integrate sensing and driving functions, resulting in its limitations in intelligent and multifunctional applications. Sliding bearings are highly dependent on the effectiveness of lubricants, and insufficient lubrication or failure can easily lead to increased friction and increased wear. The manufacturing process and precision of bearings limit their applicability in ultra-high precision applications, especially in nano-level control and positioning systems, where traditional bearings are difficult to achieve the required precision requirements. Utility Model Content

[0004] The utility model aims to provide a piezoelectric ceramic bearing to solve the problems of traditional bearings in terms of precision limitation, single function and poor performance in special environments.

[0005] To achieve the above object, the technical solution adopted by the present utility model is a piezoelectric ceramic bearing, which includes an outer bearing ring, an inner bearing ring, and balls and a cage fixed between the outer bearing ring and the inner bearing ring. Both the outer bearing ring and the inner bearing ring are made of piezoelectric ceramic materials. The piezoelectric ceramic material is a multi-layer composite structure. The balls and the cage are respectively in close contact with the second conductive layer of the outer bearing ring and the third conductive layer of the inner bearing ring. The first conductive layer of the outer bearing ring and the fourth conductive layer of the inner bearing ring are respectively fixed to external devices, and the first conductive layer and the second conductive layer are connected to each other through a metal tab. At the same time, the metal tab is connected to an external circuit.

[0006] The technical solution for achieving the object of the present utility model further includes that the piezoelectric ceramic material of the outer bearing ring from outside to inside is successively a first conductive layer, an outer piezoelectric ceramic layer, and a second conductive layer. The first conductive layer and the second conductive layer are respectively laminated on both sides of the outer piezoelectric ceramic layer to form a multi-layer composite structure.

[0007] The technical solution for achieving the object of the present utility model further includes that the piezoelectric ceramic material of the inner bearing ring from outside to inside is successively a third conductive layer, an inner piezoelectric ceramic layer, and a fourth conductive layer. The third conductive layer and the fourth conductive layer are respectively laminated on both sides of the inner piezoelectric ceramic layer to form a multi-layer composite structure.

[0008] The present invention has multiple beneficial effects and advantages compared with traditional bearings:

[0009] (1) Improving working precision and stability: The piezoelectric ceramic bearing introduces a self-sensing function, which can monitor and control the running state of the bearing in real time, improving the working precision of the bearing system and enhancing its resistance to external interference, ensuring the stable operation of high-precision equipment such as precision machine tools and nano-level processing equipment.

[0010] (2) Extending the service life of the equipment: The piezoelectric ceramic material has excellent wear resistance and corrosion resistance, and can operate stably in harsh environments for a long time, thus significantly extending the service life of the bearing. This is particularly important for applications facing challenges in high-temperature, high-pressure, or chemically corrosive environments.

[0011] (3) Improving production efficiency and the reliability of the production line: The self-sensing function of the piezoelectric ceramic bearing can detect the running state of the bearing in real time and give early warnings of potential failures, thus reducing unexpected shutdowns and maintenance time, and improving the operating efficiency and reliability of the production line.

[0012] (4) Environmentally friendly: Compared with traditional bearings, the piezoelectric ceramic bearing does not require a large amount of lubricant during operation, reducing the environmental burden that may be brought by lubricating oil pollution. In addition, the ceramic material itself has less impact on the environment, meeting the requirements of modern industry for environmental protection performance.

[0013] (5) Improve the intelligence level of the equipment: The piezoelectric ceramic bearing enables the bearing system to achieve a higher degree of intelligent and automated control through the integration of self-induction functions. This not only simplifies the equipment operation and maintenance processes but also enhances the intelligence level of the overall production system.

[0014] In summary, compared with traditional bearings, piezoelectric ceramic bearings have significant improvements and optimizations in terms of precision, stability, energy efficiency, environmental protection, and intelligence, providing important technical support and solutions for modern high-precision manufacturing and intelligent factories. Brief Description of the Drawings

[0015] Figure 1 is a cross-sectional view of the present utility model;

[0016] Figure 2 is a cross-sectional view of the piezoelectric ceramic material structure of the present utility model;

[0017] Figure 3 is the principle of piezoelectric effect Figure 1 ;

[0018] Figure 4 is the principle of piezoelectric effect Figure 2 . Detailed Description of the Preferred Embodiment

[0019] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0020] As Figure 1 shown, a piezoelectric ceramic bearing according to the present utility model includes an outer bearing ring 1, an inner bearing ring 3, and balls and a cage 2 fixed between the outer bearing ring and the inner bearing ring. Both the outer bearing ring 1 and the inner bearing ring 3 are made of piezoelectric ceramic material, and the piezoelectric ceramic material is a multi-layer composite structure. The balls and the cage 2 are respectively in close contact with the second conductive layer 13 of the outer bearing ring and the third conductive layer 31 of the inner bearing ring. The first conductive layer 11 of the outer bearing ring and the fourth conductive layer 33 of the inner bearing ring are respectively fixed to external equipment, and the first conductive layer 11 and the second conductive layer 13 are connected to each other through a metal tab 14. At the same time, the metal tab 14 is connected to an external circuit.

[0021] The working principle of a piezoelectric ceramic bearing is to utilize the piezoelectric effect to regulate the friction, vibration, and position of the bearing. By controlling the electric field applied to the piezoelectric ceramic material, the frictional force of the bearing can be adjusted, thereby achieving precise motion control and vibration reduction. This bearing technology is particularly suitable for applications that require high precision, low vibration, and long lifespan, such as precision machinery, optical equipment, etc. The principle of the piezoelectric effect can be specifically explained as follows:

[0022] Piezoelectric ceramics are usually composed of ferroelectric ceramics, such as lead zirconate titanate (PZT), etc. These materials have a complex crystal structure and exhibit non-centrosymmetry. Non-centrosymmetry is the basis of the piezoelectric effect, which causes an electric dipole moment to exist inside the material without stress. In the absence of an external electric field and stress, the centers of positive and negative charges inside the piezoelectric ceramic are in equilibrium. The positions of these charge centers determine the electrical properties of the material. When a mechanical stress (such as pressure or tension) is applied to the piezoelectric ceramic, the ceramic structure will undergo a small deformation. This deformation causes the positions of the charge centers inside the crystal to move or change. For example, when pressure is applied, it will cause the relative displacement of the centers of positive and negative charges. Due to the movement of the charge centers, a potential difference or voltage is generated between the positive and negative charges, as Figure 3 and Figure 4 . This voltage can form an electric circuit under the connection of conductive materials. Connecting a load resistor to both ends of the piezoelectric ceramic can measure the voltage signal generated by the piezoelectric effect.

[0023] As Figure 2 shown, the piezoelectric ceramic material of the bearing outer ring 1 from outside to inside is successively a first conductive layer 11, an outer piezoelectric ceramic layer 12, and a second conductive layer 13. The first conductive layer 11 and the second conductive layer 13 are respectively pressed on both sides of the outer piezoelectric ceramic layer 12 to form a multi-layer composite structure. The piezoelectric ceramic layer is usually tightly combined with the first and second conductive layers by physical methods, such as hot pressing, cold pressing, etc. In some cases, adhesives can also be used, but generally, hot pressing or cold pressing connections will ensure better mechanical strength and electrical performance. This connection method makes the upper and lower conductive layers and the piezoelectric ceramic layer form a whole, which is beneficial to improving the working efficiency and stability of the device.

[0024] Similarly, the piezoelectric ceramic material of the bearing inner ring 3 from outside to inside is successively a third conductive layer 31, an inner piezoelectric ceramic layer 32, and a fourth conductive layer 33. The third conductive layer 31 and the fourth conductive layer 33 are respectively pressed on both sides of the inner piezoelectric ceramic layer 32 to form a multi-layer composite structure.

[0025] The main materials of the outer bearing ring 1 and the inner bearing ring 3 are piezoelectric ceramics with a three-layer structure. The middle layers are the outer piezoelectric ceramic layer 12 and the inner piezoelectric ceramic layer 32 respectively. The two sides of the piezoelectric ceramic material are materials with high electrical conductivity, good wear resistance and high strength. The outermost layer mainly bears external pressure and mechanical loads and needs to have good strength and hardness to protect the internal structure of the piezoelectric ceramics from external impacts and pressures. Therefore, materials with high strength and excellent electrical conductivity are selected, that is, the strength and hardness of the first conductive layer 11 are greater than those of the second conductive layer 13, and the strength and hardness of the fourth conductive layer 33 are greater than those of the third conductive layer 31.

[0026] Piezoelectric ceramics themselves are used in the middle layers of both the outer bearing ring 1 and the inner bearing ring 3. Piezoelectric ceramics have excellent piezoelectric effects and can generate changes in charge distribution under external forces, thereby adjusting the friction, vibration and position of the bearings.

[0027] Materials with high electrical conductivity and excellent wear resistance are selected for the inner layers of both the outer bearing ring 1 and the inner bearing ring 3. This layer is located inside the bearing and is in direct contact with the balls and the cage 2. It needs to be able to withstand the moving friction of the balls and frequent contacts, and at the same time ensure good electrical connection. Therefore, not only the effectiveness of charge transmission needs to be ensured, but also the ability to resist friction and wear and extend the service life of the bearing is required, that is, the wear resistance of the second conductive layer 13 is greater than that of the first conductive layer 11, and the wear resistance of the third conductive layer 31 is greater than that of the fourth conductive layer 33.

[0028] The first conductive layer 11 and the second conductive layer 13 are connected to each other by metal tabs 14. At the same time, the metal tabs 14 are connected to an external circuit. The metal tabs need to have good electrical conductivity and durability, and at the same time, their contact with the piezoelectric ceramic layer needs to be ensured to be firm and reliable during installation. These metal tabs play a connecting role and can effectively transmit the electrical signals generated by the piezoelectric effect and lead them out for subsequent circuit connection and signal processing. When an external pressure or mechanical deformation acts on the bearing, the middle piezoelectric ceramic layer will undergo a change in charge distribution or the generation of a potential difference. This change is caused by the piezoelectric effect and can generate different electrical signals according to the magnitude and direction of the stress. Through the metal tabs pre-installed on the conductive material, the electrical signals generated by the piezoelectric effect can be directly led out to the external circuit. In the external circuit, signal amplification, filtering and analysis processing can be carried out to obtain detailed information about the working state of the bearing, such as load, vibration and stress distribution, etc.

[0029] The material selection of the ball and the cage 2 is crucial to ensure its reliability and long-term stability under high-speed rotation and high-load conditions. The balls are made of ceramic materials such as zirconia or silicon oxynitride, which have excellent wear resistance and chemical stability, can effectively reduce friction losses and improve the efficiency of the bearing, and are suitable for high-load and high-speed operating conditions. The cage is made of wear-resistant materials such as high-quality steel or engineering plastics to provide good mechanical support and guiding functions, ensure the correct positioning and movement guidance of the balls in the bearing, and thus ensure the stable operation and long-term reliability of the bearing system in complex working environments.

[0030] The utility model can realize intelligent monitoring and remote diagnosis of the working state of the bearing by real-time monitoring of the electrical signals generated by the piezoelectric effect. This self-sensing function enables the bearing to independently judge its health status, give early warnings of possible faults, and take corresponding measures to prevent damage and maintenance delays. The utility model not only improves the reliability and stability of the system, but also can extend the service life of the bearing. This is particularly important for application fields that require long-term stable operation and high precision, such as aerospace, precision machinery, and scientific instruments.

Claims

1. A piezoelectric ceramic bearing, comprising a bearing outer ring (1), a bearing inner ring (3), and balls and a cage (2) fixed between the bearing outer ring and the bearing inner ring, characterized in that: The bearing outer ring (1) and the bearing inner ring (3) are both made of piezoelectric ceramic material, and the piezoelectric ceramic material is a multi-layer composite structure. The ball and the retaining frame (2) are respectively tightly fitted with the second conductive layer (13) of the bearing outer ring and the third conductive layer (31) of the bearing inner ring. The first conductive layer (11) of the bearing outer ring and the fourth conductive layer (33) of the bearing inner ring are respectively fixed to external equipment, and the first conductive layer (11) and the second conductive layer (13) are connected to each other through a metal pick (14). At the same time, the metal pick (14) is connected to an external circuit.

2. The piezoelectric ceramic bearing according to claim 1, characterized in that: The piezoelectric ceramic material of the bearing outer ring (1) comprises, from the outside to the inside, a first conductive layer (11), an outer piezoelectric ceramic layer (12) and a second conductive layer (13); the first conductive layer (11) and the second conductive layer (13) are respectively pressed onto two sides of the outer piezoelectric ceramic layer (12) to form a multi-layer composite structure.

3. The piezoelectric ceramic bearing according to claim 2, characterized in that: The first conductive layer (11) has greater strength and hardness than the second conductive layer (13).

4. The piezoelectric ceramic bearing according to any one of claims 2 or 3, characterized in that: The second conductive layer (13) has greater wear resistance than the first conductive layer (11).

5. The piezoelectric ceramic bearing according to claim 1, characterized in that: The piezoelectric ceramic material of the bearing inner ring (3) comprises, from the outside to the inside, a third conductive layer (31), an inner piezoelectric ceramic layer (32) and a fourth conductive layer (33); the third conductive layer (31) and the fourth conductive layer (33) are respectively pressed onto two sides of the inner piezoelectric ceramic layer (32) to form a multi-layer composite structure.

6. The piezoelectric ceramic bearing according to claim 5, characterized in that: The fourth conductive layer (33) has greater strength and hardness than the third conductive layer (31).

7. The piezoelectric ceramic bearing according to any one of claims 5 or 6, characterized in that: The third conductive layer (31) has greater wear resistance than the fourth conductive layer (33).

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