Vibration reduction gear capable of actively controlling rigidity

Abstract

The invention discloses a vibration reduction gear capable of actively controlling rigidity, belongs to the field of gear vibration control, and aims at solving the problems existing in vibration reduction of an existing gear. The gear comprises a gear base body, a shape memory alloy spring, a lubricating oil groove, a temperature sensor, a resistance wire and an end cover, the end cover is fixedly connected with the end face of the gear base body, and the end cover covers a groove opening of the lubricating oil groove; a lubricating oil groove is formed in the end face of the gear base body, m radially-telescopic shape memory alloy springs are evenly distributed in the lubricating oil groove along the circumference, temperature sensors and resistance wires are symmetrically arranged at the groove bottom of the lubricating oil groove, and the resistance wires are used for heating lubricating oil in the lubricating oil groove so as to control the temperature of the shape memory alloy springs. The rigidity of the spring is controlled by regulating and controlling the temperature, the inherent frequency of the gear is finally adjusted, and the purpose of vibration reduction is achieved.

Description

Technical Field

[0001] This invention relates to a vibration damping gear with actively controlled stiffness, belonging to the field of gear vibration control. Background Technology

[0002] Gear drives, with their advantages of high transmission efficiency, reliable operation, and compact structure, are now widely used in transmission systems in shipbuilding, aviation, aerospace, transportation, and chemical industries. Gear drives often operate in environments with complex excitation sources, and the vibration they generate is one of the main factors affecting the operation of mechanical equipment. Especially when resonance occurs in the gear system, the vibration amplitude far exceeds that during normal operation, causing significant damage to the gear drive system. While vibration is a common phenomenon in gear drive system operation and cannot be completely eliminated, it can be adjusted to an acceptable safety level. Given that the gear rotor is one of the core components of the transmission system, its vibration directly determines the overall reliability and stability of the equipment. Therefore, controlling the vibration of the gear rotor to ensure the safe and stable operation of the unit is a crucial and urgent problem to be solved in gear drive systems.

[0003] Domestic and international scholars have proposed several measures to control gear vibration through research:

[0004] (1) Gear modification and optimization of key gear parameters can alter the resonance range of the gear transmission system. Yu Xiaobo, in his paper "Research on Gear Modification and Modal Optimization of Centralized Transmission Systems Based on Genetic Algorithm," describes microscopic gear modification to improve dynamic characteristics and avoid resonance in the gear transmission system. However, gear modification is typically performed during the design phase, which differs significantly from the actual operation of the gear transmission system, resulting in less than ideal performance. Furthermore, many precision gears undergo modification during the design and manufacturing stages, which is no longer sufficient to meet the further requirements for low vibration and low noise in gear transmission systems. Therefore, it is not an effective vibration reduction method.

[0005] (2) Active and semi-active control methods for vibration of gear transmission systems. This method mainly refers to using an additional device to generate an excitation force opposite to the vibration of the gear transmission system to counteract the vibration. The main principle is "force-based vibration damping". In "Active vibration control of a single-stage spur gearbox", Dogruer designed a nonlinear controller with a feedforward loop to reduce the meshing vibration of the gears by adjusting the torque acting on the input gear. However, this method only has a control effect on vibrations of a certain frequency, and its vibration control capability for gear rotor systems with resonance is limited.

[0006] (3) Adding damping structures (such as damping rings, damping layers, etc.) to the gears dissipates the vibration energy of the system and reduces the amplitude of the gear transmission system in the resonance zone. Qiu Zhirui added damping rings to the bevel gears of aero engines, which effectively reduced the vibration amplitude of the gears at the resonance point. However, since the vibration of the gear transmission system in the resonance zone is usually much greater than the vibration during normal operation, and the damping structure does not change the resonance frequency of the gear transmission system, there is still a certain risk, and the safety hazard cannot be completely eliminated.

[0007] (4) Coating or processing gears with new materials (such as polymer composites, ceramic materials, magnetic materials, etc.) to absorb, dissipate, and reduce vibration and noise in the gear transmission system by utilizing the material properties. However, the method of coating or processing gears with new materials is not mature and needs to consider factors such as cost and processing technology. Therefore, this method has great limitations in engineering practice.

[0008] In summary, gear modification cannot fully consider all situations in actual engineering applications, and the results may differ significantly from the actual operating results, indicating that this method has certain limitations. Active control systems have narrow vibration reduction bandwidths and cannot eliminate safety hazards when resonance occurs. Adding damping structures can reduce the resonance amplitude of gear transmission systems, but cannot eliminate the resonance phenomenon, and certain risks still exist. The use of new materials is limited by factors such as cost and process, making it difficult to apply in engineering practice. Summary of the Invention

[0009] To address the problems existing in current gear vibration reduction systems, this invention provides a vibration-damping gear with actively controlled stiffness.

[0010] The present invention discloses a vibration damping gear with active stiffness control, comprising a gear base 8, a shape memory alloy spring 9, a lubricating oil groove 10, a temperature sensor 11, a resistance wire 12, and an end cap 14. The end cap 14 is fixedly connected to the end face of the gear base 8 and covers the groove opening of the lubricating oil groove 10.

[0011] A lubricating oil groove 10 is provided on the end face of the gear base 8. m radially telescopic shape memory alloy springs 9 are evenly distributed along the circumference of the lubricating oil groove 10. Temperature sensors 11 and resistance wires 12 are symmetrically arranged at the bottom of the lubricating oil groove 10. The resistance wires 12 are used to heat the lubricating oil in the lubricating oil groove 10, thereby controlling the temperature of the shape memory alloy springs 9. By adjusting the temperature, the spring stiffness is controlled, and finally the natural frequency of the gear is adjusted to achieve the purpose of vibration reduction.

[0012] Preferably, the shape memory alloy spring 9 is fixed by a conical fixing pin 13. m conical fixing pins 13 are evenly distributed circumferentially on the inner wall of the lubricating oil groove 10. Each conical fixing pin 13 is equipped with a shape memory alloy spring 9. The shape memory alloy spring 9 is supported between the inner and outer walls of the lubricating oil groove 10.

[0013] Preferably, the end cap 14 is provided with an oil injection hole 15 and an oil discharge hole 16, which are connected to the lubricating oil groove 10.

[0014] Preferably, the end cap 14 is bolted to the end face of the gear base 8.

[0015] Preferably, the gears provided in the gear base 8 are spur gears, helical gears, herringbone gears, bevel gears, face gears, or planetary gears.

[0016] Preferably, the lubricating oil is turbine oil, dimethyl silicone oil, magnetorheological fluid, or dimethyl silicone oil.

[0017] Preferably, the end face of the gear base 8 is provided with a lubricating oil groove 10, which is machined on one side or on both sides symmetrically.

[0018] The beneficial effects of this invention are:

[0019] (1) The present invention has a clever structural design. While retaining the general structure of the gear, the structure is partially designed so that the gear with a single function has multiple functions.

[0020] (2) The present invention can adjust the radial stiffness of the gear online during operation by adjusting the internal lubricating oil temperature, so that the natural frequency of the gear rotor can avoid the complex excitation frequency of the gear.

[0021] (3) The present invention utilizes the high damping characteristics of shape memory alloy to provide damping for gear transmission system, dissipate the vibration energy of gear transmission system, and achieve the effect of damping and vibration reduction.

[0022] (4) The present invention has a reasonable structural design. When the key components of the present invention are damaged, they can be replaced simply by removing the end cap, which greatly improves the maintainability and security of the structure.

[0023] (5) Furthermore, this invention uses eight shape memory alloy springs evenly arranged on both sides of the gear, with each spring evenly distributed on the same circumference. This arrangement not only provides horizontal and vertical rigidity of the structure but also provides cross stiffness, thereby improving the running stability of the gear rotor.

[0024] Compared with existing vibration reduction devices, the present invention has the following advantages:

[0025] (1) The active stiffness damping gear of the present invention can adjust the stiffness online, which is more flexible than the existing damping device and can adapt to different working environments.

[0026] (2) The present invention utilizes the high damping characteristics of shape memory alloy springs. Compared with existing vibration reduction devices, the present invention can not only change the stiffness of the gear rotor, but also improve the damping and vibration reduction capability of the gear transmission system, and play a certain control role in controlling the vibration of the gear.

[0027] (3) The present invention utilizes the fact that the stiffness and damping of the shape memory alloy spring change approximately linearly with temperature in the transition temperature range from martensite to austenite, thus avoiding the nonlinear vibration problem of traditional damping vibration reduction devices. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a reduction gearbox using the active control stiffness damping gear of the present invention.

[0029] Figure 2 This is an isometric side view of the active stiffness damping gear of the present invention, without end caps;

[0030] Figure 3 This is a front view of the active stiffness damping gear of the present invention, without end caps;

[0031] Figure 4 This is a front view of the active stiffness damping gear of the present invention, without the addition of shape memory alloy springs and end caps;

[0032] Figure 5 This is a schematic diagram of the end cap structure of the active stiffness damping gear of the present invention;

[0033] Figure 6 This is a flowchart of the online stiffness control of the active stiffness damping gear of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0037] Specific Implementation Method 1: The following is combined with... Figures 1 to 6 According to this embodiment, a vibration damping gear with active stiffness control includes a gear base 8, a shape memory alloy spring 9, a lubricating oil groove 10, a temperature sensor 11, a resistance wire 12, and an end cap 14. The end cap 14 is fixedly connected to the end face of the gear base 8 and covers the groove opening of the lubricating oil groove 10.

[0038] A lubricating oil groove 10 is provided on the end face of the gear base 8. m radially telescopic shape memory alloy springs 9 are evenly distributed along the circumference of the lubricating oil groove 10. Temperature sensors 11 and resistance wires 12 are symmetrically arranged at the bottom of the lubricating oil groove 10. The resistance wires 12 are used to heat the lubricating oil in the lubricating oil groove 10, thereby controlling the temperature of the shape memory alloy springs 9. By adjusting the temperature, the spring stiffness is controlled, and finally the natural frequency of the gear is adjusted to achieve the purpose of vibration reduction.

[0039] The shape memory alloy spring 9 is fixed by a conical fixing pin 13. m conical fixing pins 13 are evenly distributed along the circumference of the inner wall of the lubricating oil groove 10. Each conical fixing pin 13 is equipped with a shape memory alloy spring 9. The shape memory alloy spring 9 is supported between the inner and outer walls of the lubricating oil groove 10.

[0040] The end cap 14 is provided with an oil injection hole 15 and an oil discharge hole 16, which are connected to the lubricating oil tank 10.

[0041] The end cover 14 is bolted to the end face of the gear base 8.

[0042] The gears on the gear base 8 are spur gears, helical gears, herringbone gears, bevel gears, face gears, or planetary gears.

[0043] The lubricating oil used is turbine oil, dimethyl silicone oil, magnetorheological fluid, or dimethyl silicone oil.

[0044] The end face of the gear base 8 is provided with a lubricating oil groove 10, which is machined on one side or on both sides symmetrically.

[0045] The active control stiffness damping gear described in this invention can be used in single-stage transmission, two-stage transmission, and multi-stage transmission gear systems, etc. See [link / reference needed]. Figure 1 A schematic diagram of the reduction gearbox of the active control stiffness damping gear of the present invention.

[0046] This invention provides an actively controlled stiffness damping gear, which can be applied to vibration reduction in gear transmission systems, including single-stage, two-stage, and multi-stage transmission gear systems. It relates to the field of vibration reduction in mechanical transmission devices and features active control of gear vibration. The actively controlled stiffness damping gear can be used in both reduction gear transmission systems and speed-up gear transmission systems. Figure 1This diagram illustrates a reduction gearbox equipped with the active control stiffness damping gear described in this invention. The gearbox receives power from an external power source (such as a motor, steam turbine, or gas turbine) to the input shaft 1, driving its rotation. This rotation in turn drives the bearing 2 and the drive gear 3. The drive gear 3 meshes with the driven gear 4, which in turn rotates the output shaft 6 on the bearing 5. The output shaft 6 outputs kinetic energy to power energy-consuming machinery (such as a generator, pump, or propeller) to complete the transmission. Gear meshing is the primary excitation source of the gear transmission system. Vibration is mainly generated by the driving gear 3 and driven gear 4, and transmitted through the input shaft 1 and output shaft 6 to the input shaft bearing 2 and output shaft bearing 5. Ultimately, the vibration is transmitted to the gearbox housing 7 and radiated to other equipment. Because the vibration frequency band generated by gear meshing is complex, it can easily cause resonance in the gear transmission system, posing a significant safety risk.

[0047] The active stiffness damping gear of this invention comprises a gear base 8, a shape memory alloy spring 9, a lubricating oil groove 10, a temperature sensor 11, a resistance wire 12, and an end cap 14. A conical fixing pin 13 is installed on the gear base 8 to fix the shape memory alloy spring 9. The end cap 14 has an oil injection hole 15 and an oil drain hole 16. The end cap 14 and the gear base 8 are connected by bolts. Before installing the active stiffness damping gear of this invention, the shape memory alloy spring 9 needs to be installed on the gear base 8 first. Then, the end cap 14 is tightened to the gear base 8. Next, the oil drain hole 16 is plugged with a plug. Oil is injected into the lubricating oil groove 10 through the oil injection hole 15 until no more can be injected, ensuring that the lubricating oil groove 10 is full of oil. Finally, the oil injection hole is plugged with a plug.

[0048] Figure 6 This invention presents a flowchart of the active stiffness-controlled vibration-damping gear control process. Before operation, optimal operating temperatures are set for different excitation conditions under various working conditions, ensuring that the natural frequency of the active stiffness-controlled vibration-damping gear avoids the excitation frequencies of each working condition. During the operation of the gear rotor system, vibration data of the gear is collected in real time, and the main frequency components of the vibration are transmitted to the control system. The control system queries the database for the optimal temperature of the shape memory alloy spring 9 corresponding to each vibration frequency and compares it with the actual measured temperature to calculate the temperature difference. When the temperature difference is not zero, the temperature of the shape memory alloy spring 9 is controlled by adjusting the power of the resistance wire to adjust the gear stiffness until the temperature difference is zero. At this point, the gear vibration data and temperature data are output. The temperature sensor 11 and the resistance wire 12 can measure and adjust the lubricating oil in the lubrication oil tank 10 online to control the temperature of the shape memory alloy spring 9. Simultaneously, the shape memory alloy spring has high damping characteristics, which can provide damping for the gear transmission system and play a vibration-damping role.

[0049] This invention regulates the stiffness of the shape memory alloy spring 9 by controlling the lubricating oil temperature, thereby controlling the natural frequency of the gear and avoiding the risk of gear resonance. Simultaneously, the shape memory alloy spring 9 possesses high damping characteristics, enabling it to reduce vibration in gear transmission systems. It can be widely used in gear transmission systems to extend the lifespan of key components such as gears and bearings.

[0050] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A vibration-damping gear with active stiffness control, characterized in that: It comprises a gear base (8), a shape memory alloy spring (9), a lubricating oil groove (10), a temperature sensor (11), a resistance wire (12) and an end cover (14), wherein the end cover (14) is fixedly connected to the end surface of the gear base (8), and the end cover (14) covers the notch of the lubricating oil groove (10); The end surface of the gear base (8) is provided with a lubricating oil groove (10), and m radially retractable shape memory alloy springs (9) are evenly distributed along the circumference of the lubricating oil groove (10). The bottom of the lubricating oil groove (10) is symmetrically provided with a temperature sensor (11) and a resistance wire (12), and the resistance wire (12) is used to heat the lubricating oil in the lubricating oil groove (10), thereby controlling the temperature of the shape memory alloy spring (9). The spring stiffness is controlled by adjusting the temperature, and finally the natural frequency of the gear is adjusted to achieve the purpose of vibration reduction.

2. A vibration-damping gear with active stiffness control according to claim 1, characterized in that: The shape memory alloy spring (9) is fixed by a conical fixing pin (13). m conical fixing pins (13) are evenly distributed along the circumferential direction on the inner groove wall of the lubricating oil groove (10). Each conical fixing pin (13) is installed with a shape memory alloy spring (9). The shape memory alloy spring (9) is supported between the inner and outer groove walls of the lubricating oil groove (10).

3. A vibration-damping gear with active stiffness control according to claim 2, characterized in that: The end cover (14) is provided with an oil filling hole (15) and an oil discharge hole (16), and the oil filling hole (15) and the oil discharge hole (16) are communicated with the lubricating oil groove (10).

4. The vibration-damping gear with active stiffness control according to claim 1, characterized in that: The end cover (14) is connected to the end surface of the gear base (8) by bolts.

5. The vibration-damping gear with active stiffness control according to claim 1, characterized in that: The gears provided on the gear base (8) are spur gears, helical gears, herringbone gears, bevel gears, face gears or planetary gears.

6. The vibration-damping gear with active stiffness control according to claim 1, characterized in that: The lubricating oil is turbine oil, dimethyl silicone oil, magnetorheological fluid or dimethyl silicone oil.

7. The vibration-damping gear with active stiffness control according to claim 1, characterized in that: The end surface of the gear base (8) is provided with a lubricating oil groove (10) which is processed on one side or symmetrically on both sides.

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