环境温度对乘用车轮毂轴承摩擦能耗的影响试验研究

Test study on effect of ambient temperature on the friction energy loss of passenger car wheel hub bearings

轮毂轴承是汽车底盘车轮上重要的零部件,为了降低汽车单位里程油耗或电耗,对在行车过程中环境温度对车轮轮毂轴承摩擦力矩和摩擦能耗的影响进行了研究。首先,给出了2种轮毂轴承摩擦力矩理论计算公式,提出了轮毂轴承摩擦能耗试验评估计算方法;然后,根据公式及相关原理对环境温度影响轮毂轴承摩擦能耗进行了理论分析,得出了初步结论;最后,利用目前国际最先进的轮毂轴承摩擦力矩及能耗试验设备,设置了特定路谱试验程序,按照恒定车速、中国路谱轻型汽车循环乘客试验(CLTC-P)和欧洲路谱新标欧洲循环测试(NEDC)试验条件,分别在不同的温度环境下进行了试验验证。研究结果表明:汽车在恒定车速下行驶,环境温度越高,轮毂轴承摩擦力矩越小,在40℃高温环境下,轮毂轴承摩擦力矩比-20℃低温下的摩擦力矩降低了约50%;汽车无论是按照CLTC-P路谱还是NEDC路谱行驶,环境温度越高,轮毂轴承摩擦能耗越小,在40℃高温环境下,轮毂轴承摩擦能耗比-20℃低温下的摩擦能耗降低了约60%,这也是汽车在冬天时单位里程油耗或电耗比夏天高的原因之一。

Wheel hub bearings are important components on the chassis of automobiles.In order to reduce fuel or electricity consumption per unit mileage of automobiles,the influence of environmental temperature on the friction torque and friction energy loss of wheel hub bearings during driving were studied.Firstly,two theoretical calculation formulas for the friction torque of wheel hub bearings were presented,and a calculation method for evaluating the friction energy loss of wheel hub bearings was proposed.Then,based on the formulas and relevant principles,a theoretical analysis was conducted on the impact of environmental temperature on the friction energy loss of wheel hub bearings,and preliminary conclusions were drawn.Finally,using the most advanced international wheel hub bearing friction torque and energy loss testing machine,a specific road spectrum test program was set up,and test verification was conducted under different temperature environments under constant vehicle speed,Chinese road spectrum China light-duty vehicle test cycle-passenger(CLTC-P),and European road spectrum new European driving cycle(NEDC)test conditions.The research results show that when a car is driven at a constant speed,the higher the ambient temperature,the smaller the friction torque of the wheel hub bearing.The friction torque of the wheel hub bearing is about 50%lower in a high temperature environment of 40℃than in a low temperature environment of-20℃.Whether a car is driven on the CLTC-P or NEDC road spectrum,the higher the ambient temperature,the lower the friction energy loss of the wheel hub bearing.In a high temperature environment of 40℃,the friction energy loss of the wheel hub bearing is about 60%lower than that in a low temperature environment of-20℃.This is also one of the reasons why the fuel or electricity consumption per unit mileage of a car is higher in winter than in summer.