Chapter 9 Operational Performance Section 2 Fuel Economy 4.2 Automobile Aspect It necessary to improve all the major components of the automobile in order to reduce fuel consumption substantially. 4.2.1 Engine aspect 4.2.2 Chassis aspect (1)The load or the total weight of automobiles or trailers (2)Air resistance factors CD and A (3)Transmission System 机械与电子工程学聚 《汽车拖拉机学》 Northwest A&F University
《汽车拖拉机学》 Northwest A&F University Chapter 9 Operational Performance 4.2 Automobile Aspect It necessary to improve all the major components of the automobile in order to reduce fuel consumption substantially. 4.2.1 Engine aspect 4.2.2 Chassis aspect (1) The load or the total weight of automobiles or trailers (2) Air resistance factors CD and A (3) Transmission System Section 2 Fuel Economy
Chapter9 Operational Performance Section 3 Tractive Property 1.Tractive Efficiency and Power Equilibrium of Tractors 1.1 Power Equilibrium of Tractors 1.1.1 Power equilibrium of wheeled tractors N。=W。+N。+Nr+Nz In the formula: N.=(1-.).N.-Wasted power of transmission system; Ns=PVWasted power caused by sliding of driving wheels; N,=P,V-Wasted power due to overcoming the overcome rolling resistance of tractors; N,=p,·V—Power used to pull farm tools. 1.1.2 Power equilibrium of crawler tractors N。=N。+N,+N。+Nr+N, 械电子工程学度 《汽车拖拉机学》 Northwest A&F University
《汽车拖拉机学》 Northwest A&F University Chapter 9 Operational Performance Ne = Nc + N + N f + NT ( ) Nc c Ne = 1− N Pq V = 1. Tractive Efficiency and Power Equilibrium of Tractors 1.1 Power Equilibrium of Tractors 1.1.1 Power equilibrium of wheeled tractors In the formula: ——Wasted power of transmission system; ——Wasted power caused by sliding of driving wheels; N f = Pf V NT = PT V ——Wasted power due to overcoming the overcome rolling resistance of tractors; ——Power used to pull farm tools. 1.1.2 Power equilibrium of crawler tractors Ne = Nc + Nl + N + N f + NT Section 3 Tractive Property
Chapter 9 Operational Performance Section 3 Tractive Property 1.2 Tractive Efficiency A variety of corresponding efficiency concepts are introduced to measure the various types of losses. Transmission efficiency n is used to measure the loss caused by transmission system.It usually considered to be a constant because its change is small,for the tractor,n0.9. Track efficiency n is used to measure the loss caused by track.It also considered to be a constant because its change is also small, commonly n0.96-0.97,for wheeled tractors,n=1. 《汽车拖拉机学》 Northwest A&F University
《汽车拖拉机学》 Northwest A&F University Chapter 9 Operational Performance 1.2 Tractive Efficiency A variety of corresponding efficiency concepts are introduced to measure the various types of losses. Transmission efficiency ηc is used to measure the loss caused by transmission system. It usually considered to be a constant because its change is small, for the tractor, ηc ≈0.9. Track efficiency ηl is used to measure the loss caused by track. It also considered to be a constant because its change is also small, commonly ηl ≈0.96—0.97, for wheeled tractors, ηl =1. Section 3 Tractive Property