双轮铣槽机铣轮系统动力学特性研究

发布时间：2018-03-05 20:10

本文选题：双轮铣槽机　切入点：短纤维增强橡胶　出处：《武汉大学》2014年博士论文　论文类型：学位论文

【摘要】：双轮铣槽机是专用防渗连续墙施工设备,国内地下工程的高速发展导致该设备市场需求日趋旺盛,然而,我国目前尚不具备研制和生产具有自主知识产权的同类型产品的能力,因此,其国产化研制已成为亟需解决的重要问题。铣轮系统是双轮铣槽机设计难度最大的核心系统之一。设备成槽尺寸限制了系统的设计空间,导致其传动系统无法直接承受岩土铣削作业时产生的重载、随机和冲击的外部激励,因而需在刀具和传动系统之间设置减振环节,形成了一条岩土→刀具→减振→传动→驱动的载荷传递路线。其中,减振系统和传动系统是该载荷传递路线中两个极其重要的子系统,其动态特性直接影响着铣轮系统铣削功能的实现以及整机运行的可靠性、稳定性和寿命,研究并改善减振系统和传动系统的动力学特性是实现双轮铣槽机国产化研制所必须解决的两个关键问题。本文结合理论建模、数值分析和物理实验,对双轮铣槽机工作装置铣轮系统的动力学特性,包括橡胶减振系统减振与隔冲特性,以及多级行星齿轮传动系统动态特性和均载特性,进行了较为深入的研究,从而为双轮铣槽机国产化研制和铣轮系统动力学特性改善提供了理论依据和技术支持。论文主要研究内容与成果如下： 1.针对铣轮橡胶减振系统的两种减振材料,即各向同性天然橡胶(NR60)和各向异性短纤维增强橡胶(FR75),研究了NR60材料静态和动态力学性能的计算方法,在此基础上,通过在超弹性和弹塑性模型中加以表征纤维方向的单元,建立了FR75材料的各向异性超弹性—粘弹性—弹塑性一维叠加力学模型；通过拟合材料静态和动态力学实验数据,完成了两种橡胶材料模型的参数辨识,验证了所建模型的正确性,为铣轮减振系统在实际工况下的减振和隔冲性能分析提供了材料参数。 2.规划了铣轮橡胶减振系统的动态设计流程,按此流程,分析了系统铣削作业时的外部激励,综合考虑成槽尺寸和传动系统设计空间等约束条件,依次确定了铣轮橡胶减振系统的设计要求,结构形式及其尺寸边界条件,建立了系统的有限元模型,实现了橡胶材料各向异性及其叠加力学性能的材料属性配置,对系统的动态响应进行了求解和分析。结果表明,NR60和FR75材料均能满足系统的减振性能需求,但针对铣轮系统的重载铣削工况,FR75材料在强度方面具有明显优势,因此更适合作为系统的减振材料；随着截面橡胶厚度的增大,系统周向隔振系数减小,冲击衰减时间增长,经比较,橡胶厚度为15mm时系统的综合性能最佳；通过增加系统轴向内外圈壳体间的橡胶厚度,有效改善了系统橡胶材料的受力状态。最终完成了系统的动态设计,并应用于铣轮系统样机制造中,实践证明,该设计能够满足系统减振和传递扭矩的要求。 3.通过分析铣轮传动系统的设计要求和约束条件,确定了系统的传动方案；采用集中质量法,建立了铣轮两级行星齿轮传动系统包含级间耦合刚度、时变啮合刚度、啮合误差以及齿侧间隙的纯扭转非线性动力学模型,并运用第二类Lagrange方程推导了对应的系统运动微分方程。此动力学模型和运动微分方程适用于任意级数、任意行星轮个数以及任意功率流形式的多级行星齿轮传动系统,为考察铣轮传动系统非线性动态特性提供了理论模型。 4.基于铣轮两级行星齿轮传动系统纯扭转动力学模型,采用Gill积分法对系统的非线性动态响应进行了求解；结合全局分岔图,分析了激励频率、啮合阻尼比以及齿侧间隙对系统分岔与混沌特性的影响,探索了系统进入混沌运动的途径。结果表明,系统处于混沌运动状态时,构件的振动响应幅值远大于系统处于稳定周期运动状态时的响应幅值；从抑制混沌的角度出发,系统的输入转速应避开255r/min~310r/min,380r/min~390r/min和570r/min~615r/min范围；随着啮合阻尼比的增大,系统非周期运动范围及其动态响应幅值呈减小趋势；减小齿侧间隙,有利于改善系统的动态特性。 5.在铣轮两级行星齿轮传动系统纯扭转动力学模型的基础上,通过附加考虑系统各中心构件的横向振动位移,建立了系统平移—扭转耦合动力学模型,基于此模型,对系统的动力学均载系数进行了数值求解与分析。结果表明,增大负载和浮动一个或多个中心构件可改善系统均载性能,对于铣轮传动系统,同时浮动太阳轮和行星架时系统的均载性能最好；在满足静态强度条件时,减少行星轮个数有利于提升系统的均载性能；相比于装配误差和齿厚偏差,构件的加工误差对系统均载性能影响最大。以上结论在系统样机研制中得到了良好验证,有效改善了铣轮传动系统的均载性能和承载能力。
[Abstract]:The slotting machine is a special construction equipment of continuous wall seepage, the domestic high-speed development of underground engineering in the equipment market needs more and more, however, China currently does not have the ability, development and production of the same type of products with independent intellectual property rights, therefore, the domestic research has become an important problem to be solved urgently.
Milling wheel system is one of the slotting machine design difficulty. Maximum core system equipment slot size limits the system design space, resulting in the transmission system can not bear rock milling operations directly overloading, and the impact of random external excitation, and therefore need to set the vibration between the tool and the link in the transmission system, the formation of a transmission line load of rock and soil, and to drive to drive the tool vibration. The vibration control system and transmission system is the transmission of the two important subsystems in the load line, its dynamic characteristics directly affect the milling gear milling function and the reliability of machine operation, stability and life dynamics and improve the damping system and transmission system are the two key problems to realize the localization of double wheel groove milling machine developed to solve.
This paper combines the theory analysis and numerical modeling, physical experiment, dynamic characteristics of wheel groove milling machine milling device of wheel system, including rubber vibration isolation and damping characteristics of punching and multi-stage planetary gear transmission system, dynamic characteristics and load characteristics are studied, which provides theoretical basis and technical support for the dynamic characteristics of wheel groove milling machine developed domestically and milling wheel system improvement. The main research contents and results are as follows:
Two kinds of materials for milling wheel rubber vibration system of 1. vibration, isotropic natural rubber (NR60) and anisotropy of short fiber reinforced rubber (FR75), the calculation method of static and dynamic mechanical properties of NR60 materials, on the basis of this, through to characterization of fiber orientation in the super elastic and elastoplastic model of unit, established FR75 anisotropic hyperelastic viscoelastic elastoplastic mechanics model by fitting the superposition of one-dimensional materials; static and dynamic experimental data, complete the parameter identification of two kinds of rubber material model, validated the model, for the milling wheel vibration damping in the actual working conditions and the shock isolation performance analysis provides material parameters.
2. planning dynamic design process of milling wheel rubber damping system. In this process, the paper analyzes the external incentive system for milling operation, considering the slot size and transmission system design space constraints, in order to determine the design requirements of milling wheel rubber damping system, structure and size of boundary conditions, established the finite element the model of the system, the material properties of rubber material configuration anisotropy and superposition mechanical properties, solution and analysis the dynamic response of the system. The results show that the NR60 and FR75 materials can meet the demand of performance of vibration reduction system, but the conditions for heavy milling milling wheel system, the FR75 material has obvious advantages in strength therefore, more suitable for damping material system; with the increase of the thickness of the rubber section, system circumferential isolation coefficient decreases, the impact of the decay time of growth, by comparison, thick rubber For the comprehensive performance of 15mm system when the best; by increasing the thickness of rubber outer ring axial shell, effectively improve the stress state of the system of rubber materials. The final completion of the dynamic design of the system, and applied to the milling wheel system prototype, practice has proved that the design can meet the system vibration and torque the requirements.
3. through the design requirements analysis of milling wheel transmission system and constraint conditions, determine the transmission scheme of the system; using the lumped mass method, a milling wheel two stage planetary gear system includes coupling stiffness, time-varying meshing stiffness meshing error and pure torsion backlash to nonlinear dynamic model, and the use of second types of Lagrange equation deduced the differential equations of motion of the corresponding differential equations. The dynamics model and motion for arbitrary series multistage planetary gear transmission system flow form any number of planetary gear and arbitrary power, provides a theoretical model for the study of nonlinear dynamic characteristics of milling wheel drive system.
Based on the 4. round of the two stage planetary gear milling system pure torsional dynamic model, the nonlinear dynamic response was solved by Gill integral method; combined with the global bifurcation graph, analyzes the influence of excitation frequency, damping ratio and meshing backlash of bifurcation and chaos, explore the route leading to chaotic motion. The results show that the system is in chaos state, the amplitude is far higher than the system in response amplitude stable periodic motion response of the vibration component; from the point of view of suppressing chaos angle, input speed of the system should avoid 255r/min~310r/min, 380r/min~390r/min and 570r/min~615r/min; with the meshing damping ratio increases, the amplitude of non periodic responses decreased range of motion and the dynamic system; reduce tooth side clearance, to improve the dynamic characteristics of the system.
In the 5. round of the two stage planetary gear milling system of pure torsion based on a kinetic model, through the additional consideration of transverse vibration displacement of the center of the system components, a coupling dynamics model of reverse translation system, based on this model, the system dynamic load sharing coefficient was solved with numerical analysis. The results show that the increase of load and floating one or more central component can improve system load performance for milling wheel transmission system, while the floating sun gear and the planetary gear system are set in the best performance; meet the static strength conditions, load sharing properties to reduce the number of star wheel is conducive to enhancing the system; compared to the assembly error and tooth thickness deviation of machining error component on system load sharing characteristics of the greatest influence. In the above conclusion system prototype has been verified, can effectively improve the milling wheel driving system of load performance and bearing Ability.

【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU69

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