带式啮合介质齿轮传动的接触分析

发布时间：2018-12-06 15:25

【摘要】：齿轮是依靠它的具有严格一定的几何曲面和一定机械强度的固体材料做成的轮齿进行力和运动传递的固体接触传动。带式啮合介质齿轮传动是一种新型的齿轮传动，其显著特征是在传统齿轮副中的一个齿轮上活套一封闭环状的柔性平带，在齿轮运转过程中，由齿轮的轮齿自然地将柔性带依次地嵌入两啮合齿面间，成为一对金属轮齿的啮合介质。这种齿轮传动由于轮齿间非金属介质带的存在，两金属表面不直接接触，，齿轮副的接触转化为“高模量（齿轮）-低模量（带）”的接触。正是这种接触副类型的改变使得轮齿齿面不易损坏、减振降噪，轮齿的制造精度要求随之降低，制造成本也将大大降低。与普通渐开线齿轮相比，带式啮合介质齿轮传动的接触特性、金属与非金属摩擦副的摩擦特性、轮齿及介质带温升情况等如何，均是本课题研究的中心内容。 1.基于Merritt理论，初步建立了带式啮合介质齿轮传动的简化接触模型，为带式啮合介质齿轮传动金属轮齿与非金属带构成的摩擦副之间的摩擦特性与润滑机理研究、啮合轮齿间相应的数学—力学模型的建立奠定了基础。运用经典接触力学方法与初等方法对简化模型的接触应力进行计算分析，为带式啮合介质齿轮传动的接触强度计算提供了理论依据。 2.对金属与非金属组成的摩擦副的摩擦磨损机理进行了探讨，在介质带受力分析的基础上，分析了介质带的失效形式。 3.基于ANSYS Workbench数值分析程序，首次建立带式啮合介质齿轮接触有限元模型，得到轮齿等效应力、接触应力等值线图以及齿轮、介质带的变形图，并与同参数同工况的普通渐开线齿轮的最大接触应力进行了对比，结果表明：由于柔性介质带的存在，带式啮合介质齿轮的接触应力降低，与理论预测一致。 4.采用有限元方法分析了介质带的各种性能参数对齿轮传动性能的影响，结果表明：介质带弹性模量、介质带厚度、介质带与轮齿间的摩擦因数等参数对齿轮承载能力均有影响，其中介质带弹性模量对轮齿齿面接触应力影响较大；带式啮合介质齿轮传动的承载能力大小与介质带参数的变化并非是线性关系，需综合考虑其接触强度、弯曲强度及传动的平稳性等，进行综合优化，选择最佳性能的介质带。 5.对带式啮合介质齿轮三维稳态温度场进行了有限元数值模拟，得到了轮齿本体温度场的分布规律，并与同工况下的普通渐开线齿轮稳态温度场进行对比分析，结果表明：介质带的存在对齿轮轮齿的温度场分布规律基本没有影响，但是会减小轮齿接触面的最大本体温度。介质带在高速运转的情况下也会产生很大的温升，对流换热系数、摩擦因数、环境温度及主动轮转速等参数对介质带的温升均有影响。因此建议把带式啮合介质齿轮传动应用于中低速传动的场合，以使介质带的温升减小，更好的发挥其功效。
[Abstract]:Gear is a kind of solid contact transmission which is made of solid material with strict geometric surface and certain mechanical strength. The belt meshing medium gear transmission is a new type of gear transmission, which is characterized by a closed ring flexible flat belt on one of the traditional gear pairs. The flexible belt is naturally embedded between the two meshing surfaces from the gear teeth to become the meshing medium for a pair of metal gear teeth. Due to the existence of non-metallic medium belt between gear teeth, the contact between the two metal surfaces is not directly contacted, and the contact of the gear pair is transformed into "high modulus (gear) -low modulus (belt) contact". It is the change of the type of contact pair that makes the tooth surface not easy to be damaged, reduces the vibration and noise, reduces the precision requirement of the gear tooth, and the manufacturing cost will be greatly reduced. Compared with the common involute gear, the contact characteristics of the belt meshing medium gear transmission, the friction characteristics of the metal and non-metal friction pairs, the temperature rise of the gear teeth and the medium band are all the central contents of this research. 1. Based on Merritt theory, a simplified contact model of belt meshing medium gear transmission is established, which is used to study the friction characteristics and lubrication mechanism between metal gear tooth and non-metal belt of belt meshing medium gear transmission. The establishment of the mathematical-mechanical model between the teeth of the meshing gear has laid the foundation. The contact stress of the simplified model is calculated and analyzed by using the classical contact mechanics method and the elementary method, which provides a theoretical basis for the calculation of the contact strength of the belt meshing medium gear transmission. 2. The friction and wear mechanism of the friction pair composed of metal and non-metal is discussed. Based on the analysis of the force of the dielectric belt, the failure mode of the dielectric belt is analyzed. 3. Based on ANSYS Workbench numerical analysis program, the contact finite element model of meshing medium gear is established for the first time, and the equivalent stress, contact stress isoline diagram and deformation diagram of gear and medium belt are obtained. The maximum contact stress of the common involute gear with the same parameters and the same working conditions is compared. The results show that the contact stress of the meshing medium gear decreases due to the existence of the flexible medium belt, which is consistent with the theoretical prediction. 4. The influence of various performance parameters of dielectric belt on gear transmission performance is analyzed by using finite element method. The results show that the elastic modulus of medium belt, the thickness of medium belt and the friction coefficient between medium belt and gear tooth have influence on the bearing capacity of gear. The elastic modulus of medium belt has great influence on the contact stress of gear tooth surface. The change of the bearing capacity of the belt meshing medium gear transmission is not linear. It is necessary to consider the contact strength, bending strength and the smoothness of the transmission synthetically, and to select the medium belt with the best performance. 5. The three-dimensional steady temperature field of meshing medium gear is numerically simulated by finite element method, and the distribution of temperature field of gear tooth body is obtained, and the steady temperature field of involute gear is compared with that of common involute gear under the same working condition. The results show that the existence of medium belt has no effect on the temperature field distribution of gear teeth, but it will reduce the maximum bulk temperature of gear tooth contact surface. The temperature rise of the medium belt is also very large under the condition of high speed operation. The temperature rise of the medium belt is affected by the convection heat transfer coefficient, friction coefficient, ambient temperature and rotation speed of the active wheel. It is suggested that the belt meshing medium gear transmission should be applied in the case of medium and low speed transmission in order to reduce the temperature rise of the dielectric belt and bring its effect into full play.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH132.41

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