(1)RollingResistance一F,（滚动阻力）load(W) / KNDCB0deflectiontire(h) / mmofRadial Deflection Curve of Tire轮胎径向变形曲线16Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance C D load W KN ( ) / deflection of tire h mm ( ) / Radial Deflection Curve of Tire 轮胎径向变形曲线 （1）Rolling Resistance —— F （ f 滚动阻力） 16 O A B
AnalysisEnergylosses.Duetothedeflectionoftires:（轮胎的变形）Duetothedeflectionofroadsurface:（路面的变形converted into the heat within the tires caused bythefriction of rubberparticles.由于轮胎内部橡胶分子的摩擦转化为热能。17Chapter1 AccelerationPerformance
Chapter 1 Acceleration Performance Analysis Energy losses: Due to the deflection of tires:(轮胎的变形) Due to the deflection of road surface:(路面的变形) converted into the heat within the tires caused by the friction of rubber particles. 由于轮胎内部橡胶分子的摩擦转化为热能。 17
Rolling resistancetorque一T，（滚动阻力偶矩）T, =Fz×auuOCTF2FZ18Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance FZ FZ T F a f Z Rolling resistance torque — Tf （滚动阻力偶矩） Tf a a ua u 18
WuaFP1不X1FZThemechanicsanalysisofdrivenwheel（从动轮）with constant revolution19Chapter1AccelerationPerformance
Chapter 1 Acceleration Performance FZ 1 Tf 1 FX 1 W1 FP1a u The mechanics analysis of driven wheel （从动轮 ） with constant revolution r 19
The mechanics analysis of driven wheel with constant revolutionFxr=T=→Fx =T1/Ff1RollingResistance of driven wheelassumeFn=T/rW（从动轮的滚动阻力）ua(: Tr= Fzia)Fassumef =a/r (fCoefficient of rolling resistant)滚动阻力系数1H=FzfX1Fz1Fr=Fx→Fxi=W·f →f =Fx1 /WiFxI=Fpl>Fn=w·fHor Fpi-r=T,n = Ffn-r= Fz- f-r-_Fa="→f =F,l /wlconclusion:undergivenconditions(stiff road; constant vehicle speed)Fp, oc Wi20Chapter1 AccelerationPerformance
Chapter 1 Acceleration Performance The mechanics analysis of driven wheel with constant revolution conclusion: under given conditions( stiff road; constant vehicle speed) 1 1 1 1 ( ) f Z f Z a F F T F a r F F f f Z 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 / / / f X X P Z F F F F f X X P F w P f f Z p F w f F w f f F w f F w or F r T F r F f r f F w F w P1 1 F T r f 1 f 1 F r T F T r X f X f 1 1 1 1 assume Ff1—Rolling Resistance of driven wheel （从动轮的滚动阻力） f =a/r （f—Coefficient of rolling resistant） 滚动阻力系数 assume 20