湿式多盘离合器短暂接合过程中热点生成机理研究

Study on the Hot Spot Generating Mechanism in the Process of Wet Multi-plate Clutch Temporary Engaging

为了解决湿式多盘离合器摩擦副短暂接合过程中热点生成现象,在考虑摩擦副滑动速度、波长、接触压力增长率与迁移速度、热点数之间的对应关系,建立热点生成理论的数值和有限元模型对热点产生机理问题进行规律性研究,研究表明:湿式制动器短暂接合过程中的高速滑动速度是造成严重热点现象的主要原因,滑动速度增加,增长率与临界速度也增加,对应产生的热点数越多,最大增长率对应的波长则向较小的方向移动;弹性模量越小,相同滑动速度对应下的增长率与迁移速度越小,热点生成个数也下降,临界速度提高;增加摩擦材料厚度可以显著降低增长率,但增加了最不稳定状态下的波长,增加摩擦材料厚度可以显著增加临界速度;有限元部分针对不同摩擦材料和摩擦副不同几何参数揭示了材料弹性特征和几何尺寸对热点产生的影响。

In order to solve the wet multi--plate clutch friction during the temporary engagement to generate hot phenomenon, by considering the friction sliding speed, the correspondence between the wavelength, the contact pressure growth ratio and migration speed, the number and finite element nu- merical model of hotspots generation theory are established,the regularity study of hot spot generating mechanism problem is carried out. The results show that during a high--speed sliding speed of wet brake temporary engagement is the main reason causing serious hot spot phenomenon, with the sliding speed increasing, the growth rate and the critical speed are increased, the more the number of hotspots generated corresponding to the maximum growth rate corresponding to smaller wavelengths direction. The smaller the modulus of elasticity, the smaller the rate of growth and migration under the same sliding velocity corresponding hotspots generated number also fell, the critical speed increased. The growth rate and critical speed can be significantly reduced with the thickness of the friction material in- creasing, but the wavelength under the most unstable state is increased too. Through the finite ele- ment section for different friction materials and friction pair geometrical parameter, the influence of ma- terial elastic characteristics and geometry size on the hot spots generated are revealed.