发动机无簧油封的设计开发及性能试验研究

发布时间：2018-08-08 13:46

【摘要】：发动机依靠曲轴前、后油封实现对曲轴旋转运动的密封功能,保证了发动机缸体内有良好的润滑,减低摩擦产生的功率损耗。为了满足汽车的节能减排的要求,各大汽车制造商都在千方百计的降低汽车燃料的损耗率,所以,开发具有良好密封性能的低摩擦扭矩的油封,是油封未来的一个主要的发展方向。在油封唇口部位橡胶材料性能的前提下,对油封结构进行不断优化与研究,尤其是通过对油封腰部及唇口部位的结构的改进,简化油封本身的结构,提高油封性能的可靠性,降低对轴的径向力,即可在一定程度上实现节能降耗的目的,也可改善发动机的整体性能。通过对油封结构发展历史的研究,及目前橡胶等高分子材料技术的不断发展,具有低摩擦扭矩、低径向力、结构简单的无簧油封是未来的发展方向之一。本文所开发的无簧油封是以潍柴WP12发动机的工况条件为设计输入,针对该发动机的工况设计开发一种新的无簧油封结构。主要研究内容包括以下三个方面：第一,对无簧油封结构进行设计。首先对油封结构的发展历史进行研究总结,然后以现有PTFE结构无簧油封及耐油硅橡胶端面密封式组合油封唇口部位结构为原型。结合两个密封的基本原理,在这个原型的基础之上提出一个结构模型,按照这个模型设计出几个具体的结构方案。然后,通过有限元分析等方法,从其中选出一个最佳的结构方案,并对这个方案进行详细的设计。第二,对橡胶配方进行改进。根据发动机工况的要求,结合新结构无簧油封的特点,对现有的生胶材料进行替换,并将配方做部分调整,使材料与结构能更好的互相适应,充分发挥出各自的最佳性能。第三,对样品进行试验与测试。根据详细的设计方案,加工出硫化模具,用改进后的橡胶材料硫化出符合要求的产品。选择一种相同规格、相同用途的有簧油封作为参照组,对径向力、摩擦扭矩、泵吸能力等油封的基本性能参数进行测试和理论计算。并对得出的结果进行分析比较。通过对试验结果的分析,我们可以发现,新型的无簧油封在这些性能上完全超过有簧油封。径向力和摩擦扭矩分别降低54.66%和79.4%,而泵吸流体能力提高5倍以上。这些数据表明新的无簧油封基本性能达到了设计目的,在降低了对发动机的功率损耗的同时,提高了唇口的密封性能。最后,通过对样品进行1000小时的寿命试验,证明密封性能的耐久性与稳定性,产品结构设计和橡胶配方设计完全达到了设计目的,设计目标圆满完成。
[Abstract]:When the engine relies on the crankshaft, the rear oil seal realizes the sealing function of the rotating motion of the crankshaft, which ensures good lubrication in the engine cylinder and reduces the power loss caused by the friction. In order to meet the requirements of automobile energy saving and emission reduction, all the major automobile manufacturers are trying to reduce the loss rate of automobile fuel, so the development is good. The oil seal with low friction torque and sealing performance is the main development direction of the oil seal in the future.
On the premise of the performance of the rubber material at the lip of the oil seal, the structure of the oil seal is continuously optimized and studied, especially by improving the structure of the waist and lip of the oil seal, simplifying the structure of the oil seal itself, improving the reliability of the oil seal and reducing the radial force of the shaft, and achieving the purpose of saving energy and reducing the consumption to a certain extent. The overall performance of the engine can be improved.
Through the study of the development history of oil seal structure and the development of rubber and other polymer technology, the non spring oil seal with low friction torque, low radial force and simple structure is one of the future development directions. The reed oil seal developed in this paper is designed for the design of the working condition of Weichai WP12 engine. A new spring free oil seal structure is developed. The main research contents include the following three aspects:
First, the non reed oil seal structure is designed. First, the development history of the oil seal structure is studied and summarized. Then the structure of the existing PTFE structure reed oil seal and the oil seal end seal combination oil seal is used as the prototype. Based on the basic principle of the two seals, a structural model is put forward on the basis of this prototype. Several specific structural schemes are designed according to this model. Then, through the finite element analysis and other methods, one of the best structural schemes is selected, and the scheme is designed in detail.
Second, the rubber formula is improved. According to the requirements of the engine working conditions, the existing raw rubber materials are replaced with the characteristics of the new reed oil seal, and the formula is partially adjusted to make the material and the structure better adapt to each other and give full play to their best performance.
Third, the sample is tested and tested. According to the detailed design, the vulcanization mold is processed and the modified rubber material is vulcanized to meet the requirements. A reed oil seal with the same specification and the same use is selected as the reference group to test the basic performance parameters of radial force, friction torque, pump capacity and so on. Theoretical calculation. Analysis and comparison of the results. Through the analysis of the test results, we can find that the new reed oil seal is completely over the reed oil seal. The radial force and the friction torque are reduced by 54.66% and 79.4% respectively, and the pump fluid capacity is increased by more than 5 times. These data show that the new reed oil seal is basic. The performance achieves the purpose of design, which reduces the power loss to the engine and improves the sealing performance of the lip. Finally, the durability and stability of the sealing performance are proved by the 1000 hour life test of the sample. The design of the product structure and the rubber formula design have fully achieved the design goal and the design goal is completed satisfactorily.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH136;U464.13

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