重型拖拉机湿式离合器摩擦片耐磨仿生设计与试验

Design and test of biomimetic wear resistant for wet clutch friction plate for heavy tractor

重型拖拉机湿式离合器作为动力换挡变速箱的重要执行部件,其摩擦副的磨损失效是导致传动系统整体性能下降的主要原因之一,为减少因其带来的资源和经济损失,进而设计一种耐磨离合器摩擦片。该文从仿生学角度出发,以大树蛙为对象,用扫描电镜观测其趾端,发现树蛙趾端微观结构轮廓形状有四边形、五边形、六边形,六边形结构居多且结构大小均匀其直径约为12μm,微结构的轮廓间为沟槽,沟槽宽度约为1.5μm。研究表明树蛙体表分泌的黏液在围绕着六边形结构的沟槽内循环流动,增强其在潮湿环境下的粘附力,即摩擦系数。树蛙在与湿滑基底接触时表现出很强的黏附力和摩擦力,仿生摩擦片具备这些特点更能满足传递运动和转矩的要求。通过提取树蛙趾端参数,优化摩擦片表面结构,将树蛙趾端的致密六边形沟槽分割结构进一步突出特点、简化结构,对重型拖拉机湿式离合器摩擦片表面的油槽结构进行相似设计,以此为设计思路设计了9种仿生试样并采用激光加工技术制作样件。采用微观摩擦磨损测试仪进行摩擦磨损试验,通过计算摩擦系数对比不同六边形直径与不同沟槽宽度下摩擦摩损效果上的差异。试验结果表明,仿生非光滑结构比光滑结构具有更好的耐磨性特性,且正六边形直径为12 mm,沟槽宽度为1.5 mm时,磨损量最低,摩擦系数相对较高,这因为六边形直径与沟槽宽度综合作用,能够最大限度地降低磨损,提高摩擦片的工作能力和使用寿命。这说明合理地设计摩擦片表面结构,不仅能够满足动力传递的要求,同时可以降低磨损,节省材料,进而达到了改善离合器耐磨性能的要求。

Wet clutch of heavy tractor is an important executive component of power shift gearbox.The wear failure of the friction pair is one of the main reasons for the overall performance degradation of the transmission system.To reduce the huge resource and economic loss caused by it,a wear-resistant clutch friction plate was designed.In this paper,from the perspective of bionics,the big tree frog was used as the experimental research object,and the toe end was observed by scanning electron microscopy.The microstructure of the toad end of the tree frog is quadrilateral,pentagon,hexagonal,and the hexagonal structure is mostly.The structure is uniform in size and has a diameter of about 10μm.The microstructures have a groove between the outlines and a groove width of about 1μm.Studies have shown that the mucus secreted by the body surface of the tree frog circulates in the groove surrounding the hexagonal structure,enhancing its adhesion,which is the coefficient of friction,in a humid environment.Tree frogs exhibit strong adhesion and friction when in contact with slippery substrates.With these characteristics,the bionic friction linings can better meet the requirements of transmission motion and torque.The toad parameters of the tree frog were extracted,the surface structure of the friction lining was optimized,and the dense hexagonal groove division structure of the toad end of the tree frog was further highlighted and simplified.The oil sump structure on the surface of the wet clutch friction plate of the heavy tractor was similarly designed.Nine kinds of bionic samples were designed for the design idea and the samples were made by laser processing technology.The friction and wear tests were carried out on a micro-friction and wear tester,and the differences of friction and wear with different hexagonal diameters and different groove widths were studied.The test results showed that the bionic non-smooth structure has better wear resistance than the smooth structure,and the regular hexagon has a diameter of 12 mm.When the groove width is 1.5 mm,the wear amount is the lowest and the friction coefficient is relatively high.The combined shape diameter and groove width can minimize wear and improve the service life of the friction plate,thus achieving the requirement of improving the wear resistance of the clutch.