典型一次性机械零件设计及其应用研究
发布时间：2018-10-31 11:20
【摘要】：一般常用的机械系统、设备或装置都是长期运行、反复使用的，本文称之为“常规机械”。而在某些特殊场合中，有一类机械只使用一次后就被放弃不用，这类机械被称为“一次性机械”。一次性机械中的机械零件可以笼统地称为“一次性机械零件”。一次性机械零件的设计理论和方法与常规机械零件设计方法应当有所不同，然而，由于目前并未对一次性机械零件与常规机械零件给予明确的区分，所以一次性机械零件的设计仍然沿用常规机械零件的设计思想和方法，这就导致将常规机械设计准则中用于一次性机械零件设计时，不可避免的出现设计结果冗余，造成整体设计指标下降，有时甚至无法满足设计要求。虽然采用试验样机法在一定程度上能够完成一次性机械的研制，但是该方法的研制周期较长、效率较低、成本过高，不能满足日益增加的研制任务要求。因此，有必要深入研究一次性机械零件的设计理论和方法，以便为一次性机械设计理论体系的建立打下基础。 在归纳总结常规机械零件设计准则和方法的基础上，本文将一次性机械中承受循环载荷次数少的机械零件定义为一次性机械零件，明确了一次性机械零件不同于常规机械零件的基本特征，提出了在一次性机械零件设计时应该遵循的基本原则，并通过与常规机械零件设计方法的对比计算，阐明了一次性机械零件概念提出的意义。 在提出了一次性机械零件概念的基础上，本文研究了一次性机械零件与常规机械零件的区分界限。首先，基于疲劳理论，根据机械零件失效形式的不同，将一次性机械零件划分为两类分别进行研究。特别针对发生弹性失效的情况，以常用齿轮钢40Cr为试验材料，深入研究了40Cr在较高循环应力水平下的低周疲劳失效和棘轮失效行为。根据实验结果，定义了产生0.2%的总塑性应变时所对应的循环载荷作用次数为疲劳弹性失效寿命，并用疲劳弹性失效替代疲劳断裂作为高应力作用下的一次性机械零件疲劳失效的判断依据，修正了材料在高应力作用下的疲劳失效寿命模型。为了满足一次性机械零件的高可靠性要求，在40Cr的疲劳特性研究中，根据试验结果，确定了疲劳弹性失效寿命的概率分布类型为三参数Weibull分布，并采用灰色估计和最大相关系数优化法进行了参数估计，在参数估计中依据最可靠原则来确定疲劳概型参数，在提高材料许用应力范围的同时保证一次性机械零件高可靠性要求。 本文还以直齿渐开线圆柱齿轮零件为例研究了典型一次性机械零件的设计方法。在研究过程中，规划了一次性齿轮零件的研究内容，继承和改进了常规齿轮零件设计准则和方法，，使之适用于一次性齿轮零件的设计。建立了小模数直齿渐开线圆柱齿轮的低周疲劳强度设计模型。该模型由两个子模型组成，首先建立了基于啮合过程的齿轮接触有限元仿真模型，利用该模型研究了较高载荷下齿轮的齿间载荷分布特征，分析了主要安装误差对齿轮应力状态的影响，获取齿根处应力应变信息。然后，基于FS模型和临界平面理论，利用有限元模型得到的应力应变信息，进行了齿根弯曲强度设计。为验证该疲劳强度设计模型的准确性，研制了小模数齿轮对称疲劳试验机。以40Cr小模数齿轮为试验对象，验证了所建立的疲劳强度设计模型的有效性。 开展了某型号箭用舵机减速器的研制工作，该减速器采用谐波传动形式，减速比300，具有输出80Nm扭矩的能力，总重量约1000g。在研制过程中，采用一次性机械零件设计方法，运用所建立的疲劳强度设计模型，对直筒形柔轮的进行了疲劳强度设计，最后，通过专用测试台测试了所研制的谐波减速器性能，结果表明各项指标均满足要求。
[Abstract]:The commonly used mechanical systems, equipment, or devices are long-term, repeated use, referred to herein as" General Machinery ". In some special situations, there is a class of machines that have been abandoned only once, and this type of machine is called" One-time machine ". mechanical parts in a disposable machine may be generally referred to as" One-time mechanical part". The design theory and method of the one-time mechanical part should be different from the conventional mechanical parts design method, however, since there is no explicit distinction between the one-time mechanical part and the conventional mechanical part, Therefore, the design of the one-time mechanical part still follows the design idea and method of the conventional mechanical parts, which leads to the inevitable design result redundancy when the conventional mechanical design criterion is used for the design of a disposable mechanical part, so that the overall design index is reduced, Sometimes you can't even meet the design requirements. Although the test prototype method can accomplish the development of one-time machinery to a certain extent, the development period of the method is long, the efficiency is lower, the cost is too high, and the requirements for the development task are not met. Therefore, it is necessary to study the design theory and method of one-time mechanical parts in order to lay the foundation for the establishment of one-time mechanical design theory system. On the basis of summarizing the design criteria and methods of conventional mechanical parts, this paper defines the mechanical parts with few times of cyclic loading in one-time machinery as one-time mechanical parts, and makes it clear that one-time mechanical parts are different from the basic mechanical parts. In this paper, the basic principle which should be followed in the design of one-time mechanical parts is put forward, and the concept of one-time mechanical parts is clarified by the comparison calculation with the conventional mechanical parts design method. On the basis of putting forward the concept of one-time mechanical parts, this paper studies one-time mechanical parts and conventional mechanical parts. First, based on the fatigue theory, the one-time mechanical part is divided into two categories according to the different failure modes of mechanical parts. Don't conduct the research. Especially for the case of elastic failure, the low-cycle fatigue failure and the ratchet of 40Cr at higher cyclic stress level were studied by using 40Cr as the test material. According to the experimental results, the number of cyclic loads corresponding to the total plastic strain of 0.2% is defined as the fatigue elastic failure life, and the fatigue failure is replaced by fatigue elastic failure as a one-time mechanical part fatigue failure under the action of high stress. According to the judgment basis, the fatigue loss of the material under the action of high stress is corrected. In order to meet the high reliability requirement of one-time mechanical parts, the probability distribution type of fatigue elastic failure life is determined as three-parameter Weibull distribution according to the experimental results, and the grey estimation and the maximum correlation coefficient optimization method are adopted in the study of the fatigue properties of 40Cr. Parameter estimation, based on the most reliable principle in the parameter estimation, to determine the fatigue almost-type parameter, in order to increase the allowable stress range of the material, guarantee the high-time mechanical part height Reliability requirements are also studied in this paper. The typical disposable machine is also studied in this paper. In the research process, the research contents of one-time gear parts are planned, and the design criteria and methods of conventional gear parts are inherited and improved so as to be applicable to one time. Design of gear parts with small modulus and low circumference of involute cylindrical gear with small modulus The fatigue strength design model is composed of two sub-models. First, a finite element simulation model of gear contact based on meshing process is established. The distribution characteristics of interdental load of gears under high load are studied by using this model. The main installation error is analyzed. The influence of the stress state of the wheel and the acquisition of teeth Then, based on FS model and critical plane theory, the stress strain information obtained by finite element model is used. In order to verify the accuracy of the fatigue strength design model, small modulus teeth have been developed. The fatigue strength of the wheel is verified by using 40Cr small modulus gear as the test object. The design model is effective. The development of a steering gear reducer for an arrow is carried out. The reducer is in the form of harmonic drive, with a reduction ratio of 300, and has the capability of outputting 80Nm. The strength and total weight are about 1000g. During the development process, the design method of the one-time mechanical parts is adopted, the fatigue strength design of the straight cylindrical flexible wheel is designed by using the established fatigue strength design model, and finally, the test bench is tested through the special test bench. The performance and results of the developed harmonic reduce
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH112;TH13
本文编号：2301994
[Abstract]:The commonly used mechanical systems, equipment, or devices are long-term, repeated use, referred to herein as" General Machinery ". In some special situations, there is a class of machines that have been abandoned only once, and this type of machine is called" One-time machine ". mechanical parts in a disposable machine may be generally referred to as" One-time mechanical part". The design theory and method of the one-time mechanical part should be different from the conventional mechanical parts design method, however, since there is no explicit distinction between the one-time mechanical part and the conventional mechanical part, Therefore, the design of the one-time mechanical part still follows the design idea and method of the conventional mechanical parts, which leads to the inevitable design result redundancy when the conventional mechanical design criterion is used for the design of a disposable mechanical part, so that the overall design index is reduced, Sometimes you can't even meet the design requirements. Although the test prototype method can accomplish the development of one-time machinery to a certain extent, the development period of the method is long, the efficiency is lower, the cost is too high, and the requirements for the development task are not met. Therefore, it is necessary to study the design theory and method of one-time mechanical parts in order to lay the foundation for the establishment of one-time mechanical design theory system. On the basis of summarizing the design criteria and methods of conventional mechanical parts, this paper defines the mechanical parts with few times of cyclic loading in one-time machinery as one-time mechanical parts, and makes it clear that one-time mechanical parts are different from the basic mechanical parts. In this paper, the basic principle which should be followed in the design of one-time mechanical parts is put forward, and the concept of one-time mechanical parts is clarified by the comparison calculation with the conventional mechanical parts design method. On the basis of putting forward the concept of one-time mechanical parts, this paper studies one-time mechanical parts and conventional mechanical parts. First, based on the fatigue theory, the one-time mechanical part is divided into two categories according to the different failure modes of mechanical parts. Don't conduct the research. Especially for the case of elastic failure, the low-cycle fatigue failure and the ratchet of 40Cr at higher cyclic stress level were studied by using 40Cr as the test material. According to the experimental results, the number of cyclic loads corresponding to the total plastic strain of 0.2% is defined as the fatigue elastic failure life, and the fatigue failure is replaced by fatigue elastic failure as a one-time mechanical part fatigue failure under the action of high stress. According to the judgment basis, the fatigue loss of the material under the action of high stress is corrected. In order to meet the high reliability requirement of one-time mechanical parts, the probability distribution type of fatigue elastic failure life is determined as three-parameter Weibull distribution according to the experimental results, and the grey estimation and the maximum correlation coefficient optimization method are adopted in the study of the fatigue properties of 40Cr. Parameter estimation, based on the most reliable principle in the parameter estimation, to determine the fatigue almost-type parameter, in order to increase the allowable stress range of the material, guarantee the high-time mechanical part height Reliability requirements are also studied in this paper. The typical disposable machine is also studied in this paper. In the research process, the research contents of one-time gear parts are planned, and the design criteria and methods of conventional gear parts are inherited and improved so as to be applicable to one time. Design of gear parts with small modulus and low circumference of involute cylindrical gear with small modulus The fatigue strength design model is composed of two sub-models. First, a finite element simulation model of gear contact based on meshing process is established. The distribution characteristics of interdental load of gears under high load are studied by using this model. The main installation error is analyzed. The influence of the stress state of the wheel and the acquisition of teeth Then, based on FS model and critical plane theory, the stress strain information obtained by finite element model is used. In order to verify the accuracy of the fatigue strength design model, small modulus teeth have been developed. The fatigue strength of the wheel is verified by using 40Cr small modulus gear as the test object. The design model is effective. The development of a steering gear reducer for an arrow is carried out. The reducer is in the form of harmonic drive, with a reduction ratio of 300, and has the capability of outputting 80Nm. The strength and total weight are about 1000g. During the development process, the design method of the one-time mechanical parts is adopted, the fatigue strength design of the straight cylindrical flexible wheel is designed by using the established fatigue strength design model, and finally, the test bench is tested through the special test bench. The performance and results of the developed harmonic reduce
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH112;TH13
【参考文献】
相关期刊论文 前1条
1 邓聪;;基于灵敏度分析方法的谐波减速器柔轮的疲劳强度研究[J];机械传动;2012年10期
本文编号：2301994
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