战敏 冯立 陈强 沈飞

摘 要：针对某SUV冷启动异响问题，对传动轴中间支承隔振性能进行研究。通过分析中间支承隔振原理，得出异响问题为低温时支承刚度增大、隔振性能变差导致。文章通过中间支承增加橡胶隔振垫、改变支承橡胶衬套材料两方面提高支承隔振效果，改善异響问题。验证结果表明，改变支承橡胶衬套材料改善效果明显。

关键词：传动轴中间支承;隔振原理;支承刚度;隔振性能

Abstract： Combined with a SUV cold start problem， the anti-vibration performance of the propshaft intermediate support is studied. By analyzing the vibration isolation principle of the intermediate support， it is concluded that the abnormal sound problem is caused by the increase of the support stiffness and the deterioration of vibration isolation performance at low temperature. In this paper， there are two ways to enhance the supports anti-vibration performance by changing the supports stiffness. One is increasing the rubber vibration isolation pad， the other is changing the rubber lining material of the support. The results show that the latter way has obvious improvement effect.

Keywords： Propshaft intermediate support; Vibration isolation principle; Support stiffness; Anti-vibration perfor mance

前言

传动轴是汽车动力传动系统的主要部件之一，它的动力学特性直接关系到汽车性能。传统乘用车轴距普遍较长，为提高传动轴临界转速，满足整车NVH性能以及布置要求，常将传动轴分段，需设置中间支承用于支承与定位。

传动轴有效隔振方法之一就是合理设计中间支承的刚度，支承刚度若不合理，隔振效果会大打折扣。本文结合某SUV冷启动异响问题，对传动轴中间支承隔振性能进行研究。

1 问题描述与分析

1.1 问题描述

某SUV在低于-20℃的低温环境下，车辆冷启动噪音大，且持续时间长达400s左右。声音大致来自机舱底部，热车后噪音消失。

对该SUV进行问题复现，将其在-30℃低温舱静置一夜后测试冷启动时车内振动信号，如图1所示。结果表明，冷启动时车内存在200HZ附近明显共振带。

1.2 问题分析

1.2.1 激励源分析

该SUV采用两段式传动轴，中间设置支承结构。传动轴振动噪声从变速器输出端经传动轴中间支承传递到车身，引起车内结构共鸣声或振动。鉴于异响来自机舱底部，判断异响源为传动轴中间支承。……