基于动力学耦合的高速齿轮润滑特性及空化机理研究

In recent years, high speed, long lifetime and high reliability have become an important direction for the evolvement of gear device with the development of the key areas of high speed railway, advanced CNC and wind turbines in China. As the speed increases, vibration noise, scuffing failure and cavitation erosion have become a prominent problem in gear system. The dynamic design alone has been already unable to meet the demands, so it is necessary to combine the friction lubrication problem with the dynamic design to significantly enhance the scientificalness of high speed gear design. In addition, the cavitation mechanism of high speed gear must be held in order to effectively suppress or eliminate the cavitation phenomenon. In view of the above problems, the purpose of this project is to study the high speed gear lubrication characteristics and cavitation mechanism of dynamics coupling by means of theoretical analysis, simulation and experimental test. The key research content can be listed as (i) the establishment of the tribo-dynamic coupling model for high speed gear, (ii) the implementation of high efficient and stable numerical algorithm, (iii) the analysis of the lubrication characteristics of dynamics coupling, and (iv) the formation of vibration cavitation mechanism of high speed gear. To make theoretical research apply in practice, the theoretical model is verified and modified by experiment, with a view to provide theoretical basis and analysis method for improving the lubrication performance and restraining the cavitation erosion of high speed gear system.

近年来，随着我国高速铁路、高档数控机床、风力发电等重点领域的发展，高转速、长寿命和高可靠性成为齿轮传动装置发展的重要方向。随着转速的提高，振动噪声、胶合失效、气蚀等已成为齿轮系统的突出问题。单靠动力学设计已无法满足要求，必须将摩擦润滑问题与动力学设计进行有机结合，显著增强高速齿轮设计的科学性。另外，为了有效抑制或消除气蚀现象，必须掌握高速齿轮空化的形成机理。针对上述问题，本项目拟运用理论分析、仿真模拟和实验测试相结合的研究手段，开展动力学耦合的高速齿轮润滑特性及空化机理研究。课题重点研究高速齿轮摩擦动力学耦合模型的建立，高效稳定数值算法的实现，动力学耦合的润滑特性分析及高速齿轮振动空化的形成机理。最后，通过实验测试来验证和修改理论模型，实现理论研究与实际应用的有机结合，为高速齿轮系统润滑性能的改善、气蚀的抑制提供理论支持和分析方法。

齿轮的表面疲劳、齿面磨损与冲击载荷和润滑状态紧密相关，将润滑设计与动力学设计相结合，研究齿轮啮合副摩擦动力学耦合问题，对保证高速齿轮的性能和质量具有重要应用价值。高速齿轮啮合过程中润滑油需要承受剧烈的速度和压力变化，发生空化/气蚀的几率将大大提高。因此，深入分析齿轮润滑空化机理，寻找控制气蚀的有效方法，对高速齿轮的设计、制造具有重要的理论意义和实用价值。.本性项目针对高速齿轮传动系统，围绕动力学耦合的齿轮润滑特性和空化机理两条主线开展研究工作，运用理论建模、CFD仿真和试验分析相结合的研究手段，研究摩擦动力学耦合的高速齿轮润滑特性，分析齿轮振动、表面形貌、运行工况对空化产生、发展和溃灭的影响，揭示高速齿轮振动空化演变规律。. 主要结论如下：. （1）齿轮转速越高，由于两轮齿间体积的膨胀，啮合齿腔内润滑油的压力下降越明显，导致越严重的空化，齿腔中产生的气体也越多，齿面润滑状态更恶劣。. （2）轻载情况下，齿轮容易发生大幅度振动，导致齿腔内油液压力波动剧烈，造成空化气泡的不断生成和溃灭，易对齿面造成破坏。. （3）在轮齿啮合表面，齿根附近出现的空化气体较多，而在节点附近压力波动最剧烈，意味着轮齿啮合面节点处可能最容易出现严重的空蚀。. 该项目的进行为高速齿轮的润滑设计提供关键理论和方法，研究成果有助于了解和掌握齿轮振动空化机理，提高齿轮产品的可靠性，抑制高速齿轮气蚀的发生。