汽车变速器齿轮啸叫噪声试验

为了研究汽车变速器齿轮阶次振动及其所形成的啸叫噪声特征及机理,设计整车道路实测工况试验.分析以下4个方面的变化及相互之间的联系,即变速器齿轮阶次在驾驶室内形成的啸叫噪声、齿轮阶次在发动机机舱内形成的啸叫噪声、变速器后轴承座壳体上的齿轮阶次振动和驱动车轮上的转矩.振动与噪声试验结果分析表明：在发动机机舱内或变速器内,齿轮阶次振动及形成的啸叫噪声客观上始终存在；在驾驶室内,低频率的齿轮阶次振动所形成的啸叫噪声相对于高频率的更容易出现,且汽车正驱加速过程与反拖滑行过程对比,加速过程的齿轮阶次振动更强,但形成的啸叫噪声更弱.分析以上试验结果形成的内在原因可知,即低频率阶次振动及所形成的啸叫噪声,相对高频率更易于传递至驾驶室内；低转速时的低频率阶次噪声,与总体噪声的差值更小,在人耳主观听觉上更容易被察觉；汽车在反拖滑行时,发动机油门处于停止喷油状态,驾驶室内形成的背景或总体噪声相对更小,反拖过程比加速过程更易于被人耳主观察觉到低频阶次啸叫噪声.车轮转矩试验结果表明,正驱转矩比反拖转矩大,相应的振动阶次较明显；在反拖刹车工况下,高转矩使得齿轮副阶次振动变得模糊.

Experimental study on gear whine noise from transmission in vehicle

A track running experiment was designed in order to investigate the generating mechanism of gear order vibration and its whine noise from a vehicle transmission. Gear whine noise inside passenger and engine compartments, gear order vibration on the transmission rear bearing seat and the front drive wheel torque were measured and analyzed. The vibration and noise results showed that the gear order vibration and its whine noise existed all along inside the engine compartment or just inside the transmission. Inside the passenger compartment, low frequency gear whine noise appeared more obviously and subjectively. By comparison with the coasting down condition, the gear order vibration was higher in the driving up condition. On the contrary, the gear order whine noise was lower. The root causes were analyzed. Low frequency order was more easily transferred into the passenger compartment. The difference between order and total noise was lower at the low engine speed and the low order noise was more easily perceived subjectively. In addition, the engine stopped to spray gasoline on the coasting down condition and the total noise was lower. The front wheel torque results showed that the input torque was higher and the corresponding gear order vibration was more obvious on driving up than coasting down condition. The very high input torque made the corresponding gear order vibration less unobvious on braking to coast down condition.