塑料斜齿轮啮合热力耦合数值仿真

发布时间：2018-04-28 20:42

本文选题：塑料斜齿轮 + 摩擦生热　；参考：《湘潭大学》2012年硕士论文

【摘要】：齿轮传动是一种应用最为广泛的传动机构，其用途主要有两个：传递运动和传递动力。因其具备传动比大、准确度高、效率高、平稳度高、使用寿命长、结构紧凑和安全可靠度高等优点被广泛应用到生产和生活中。随着材料科学的发展以及对工业产品轻量化要求的提高，工程塑料在齿轮生产中的应用越来越广泛。塑料齿轮与传统金属齿轮相比拥有很多优点，但是由于自身材料属性所限，塑料齿轮在实际使用过程中也会暴露出一些不足之处。塑料自身具有较高的热敏感性及较低的疲劳强度，因此塑料斜齿轮会比传统金属齿轮更容易产生轮齿断裂、疲劳变形或者胶合等。本文将塑料斜齿轮副在匀速啮合情况下的摩擦生热特性作为研究对象，主要的研究内容和结论如下： 1．简要介绍了塑料斜齿轮传动的传动特点、国内外研究现状、有限元方法的发展及其基本原理、当前市场上普遍使用的几款有限元软件及其特点；确定本文使用LS-DYNA程序进行塑料斜齿轮副啮合过程摩擦生热动力学仿真。 2．对塑料斜齿轮副啮合过程中的齿面的接触原理及摩擦生热机理进行分析，完成了对齿面接触应力的计算，建立了斜齿轮副啮合的摩擦热流量模型，从理论上对有限元摩擦及传热分析原理进行探讨，并对有限元法及有限元软件中的接触理论、摩擦及传热分析原理及求解过程进行介绍。完成了一套有效的处理塑料斜齿轮副传动过程中齿面摩擦生热热力耦合问题的方法。 3．综合使用多种CAD/CAE软件完成塑料斜齿轮副传动过程中齿面的摩擦生热有限元分析。使用SolidWorks建立塑料斜齿轮的三维几何模型并完成其装配，，在HyperMesh软件中完成斜齿轮副摩擦生热有限元模型的建立，最终在LS-DYNA软件中完成斜齿轮在干摩擦情况下匀速啮合过程中摩擦生热的仿真模拟。在高效的完成了数据在各个软件之间的传输的同时，提高了有限元模拟计算的效率和精度，为其他工程人员使用有限元方法解决其他工程问题提供了借鉴。 4．对主动轮转速为60r/min，从动轮阻力矩为10N m工况下斜齿轮啮合齿面瞬时温度分布及变化情况进行详细分析。发现温升主要集中在轮齿表面，并且由于MC尼龙本身具有较低的热传导系数，热量扩散的很慢；得到斜齿轮齿面经过一次摩擦之后温度场的分布情况及其随时间变化的规律；发现由于齿轮各轮齿在啮合过程中产生摩擦热流量相差很小，导致的齿面升温幅度很接近；轮齿啮合的啮入点和啮出点产生的摩擦热流量要远大于其他位置产生的摩擦热流量，因此齿面的最高瞬时温升出现在齿轮的啮入点和啮出点附近，最高可温升为0.74K。 5．对主动轮不同转速和从动轮受不同阻力矩的齿轮啮合情况进行仿真模拟，进一步考虑主动轮转速和从动轮所受阻力矩对MC尼龙斜齿轮副啮合过程中齿面升温的影响。通过计算可知，主动轮转速是影响齿面啮入点温升所需时间的主要因素，并且随着转速的增加，齿面温升速率近乎线性增加；在主动轮转速一定的情况下，随着从动轮加载阻力矩的增大，啮入点温升时间会有小幅度的增加，这跟时间步长的确定及齿面变形增大有关。主动轮的转速及从动轮所受阻力矩的增加都能导致轮齿表面瞬时温度的增加，只是整个过程增加幅度有所降低，并且从动轮所受阻力矩对齿面啮合区内温度的升高影响更加显著一些。从能量守恒的角度对各种工况下MC尼龙斜齿轮的热寿命进行粗略估算，对保证MC尼龙斜齿轮的安全使用有一定的参考价值。
[Abstract]:Gear transmission is one of the most widely used transmission mechanisms . It has two main uses : transfer motion and transmission power . Because of its high transmission ratio , high accuracy , high efficiency , high stability , long service life , compact structure and high reliability , it has been widely used in production and life .

With the development of material science and the improvement of light weight requirement for industrial products , the application of engineering plastics in gear production is more and more extensive .

1 . This paper briefly introduces the transmission characteristics of plastic helical gear transmission , the research status at home and abroad , the development of finite element method and its basic principle , and several finite element software and its features widely used in the current market .
In this paper , the LS - DYNA program is used to simulate the friction and thermal dynamics of the secondary meshing process of the plastic helical gear .

2 . The contact principle of the tooth surface and the mechanism of friction and heat generation in the auxiliary meshing process of the plastic helical gear are analyzed , the friction heat flow model for the tooth surface contact stress is established , the theory of finite element friction and heat transfer analysis is discussed , and the contact theory , the friction and the heat transfer analysis principle and the solving process in the finite element method and the finite element software are introduced .

3 . Using several CAD / CAE software to complete the finite element analysis of the tooth surface in the auxiliary transmission process of the plastic helical gear , a three - dimensional geometric model of the plastic helical gear is established and the assembly is completed . The simulation simulation of the friction heat generation during the uniform speed meshing process of the helical gear is completed in the HyperMesh software . At the same time , the efficiency and accuracy of the finite element simulation calculation are improved in the LS - DYNA software , and the finite element method is used for other engineering personnel to solve other engineering problems .

4 . The instantaneous temperature distribution and the change of the meshing tooth surface of the helical gear are analyzed in detail in the condition that the rotation speed of the driving wheel is 60r / min , the torque of the driven wheel is 10 N m , and the temperature rise is mainly concentrated on the surface of the gear teeth , and the MC nylon has a low thermal conductivity coefficient , and the heat diffusion is very slow ;
obtaining the distribution of the temperature field after one - time friction of the bevel gear tooth surface and the law of changing over time ;
It is found that the frictional heat flux generated by the gear teeth of the gear is very small during the meshing process , and the temperature rise of the tooth surface is very close ;
the frictional heat flux generated by the meshing point and the meshing point of the gear teeth is far greater than the frictional heat flow generated by other positions , so that the highest instantaneous temperature rise of the tooth surface appears in the vicinity of the meshing point and the meshing point of the gear , and the maximum temperature rise is 0.74K .

5 . The influence of the rotation speed of the driving wheel and the torque of the driven wheel on the temperature rise of the tooth surface during the meshing process of the MC nylon helical gear is further studied by simulating the meshing of the driving wheel with different rotating speed and the driven wheel .
Under the condition that the rotation speed of the driving wheel is certain , the temperature rise time of the meshing point increases with the increase of the loading resistance moment of the driven wheel , which is related to the determination of the time step and the increase of the deformation of the tooth surface .

【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH132.41

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