1. 2. 3. 4.
These parts can be grouped into four major categories; body, engine, chassis and electrical system.
The internal combustion engine is most common; this obtains its power by burning a liquid fuel inside the engine cylinder. The chassis includes the power train, steering, suspension, and braking systems.
A power train can include a clutch for manual transmission or a torque converter for automatic transmission, a transmission, a drive shaft, final drive and differential gears and driving axles.
5. 6.
Basic types are: leaf springs, coil springs and torsion bars.
A basic ignition system consists of the battery, low-lension cables, the ignition coil, distributor, coil high-tension cable, spark plug cables and spark plugs.
7. 8. 9. 10. 11. 12. 13. 14. 段落
The operating strokes are: induction stroke, compression stroke, power stroke, exhaust stroke.
The major parts of engine are engine block, engine heads, pistons, connecting rods, crankshaft and valves.
These systems are the fuel system, intake system, ignition system, cooling system, lubrication system and exhaust system. The dry clutch mechanism includes three basic parts: driving member, driven member and operating members.
The spur gears are mounted on four shafts: primary shaft (input shaft), layshaft (countershaft), mainshaft, and reverse idler shaft.
The three types of braking systems are in use today: service braking system, parking braking system and additional retarding-braking system. It has five basic parts: the receiver, expansion valve, evaporator, compressor, and condenser. The three normally adjustable angles are caster, camber, and toe.
一．Elements of the Power Train
The elements of the power train must meet the following requirements; 1) 2) 3) 4) 5) 6)
enable driving away, convert torque and speed,
enable different directions of rotation for driving forward and backward, transmit tractive and pushing forces,
permit different rotational speeds of the drive wheels when cornering,
guarantee optimum operation of the engine (or electric motor ) in terms of fuel consumption and exhaust emissions.
Standstill, driving-away and power interruption are made possible by operation the clutch .During driving away, the clutch slips and bridges the difference in rotational speed between engine and power train. When different operating conditions call for a shift of gear, the clutch separates the power train during shifting.
Engine torque and engine speed are converted in the transmission in accordance with the tractive-power demand of the vehicle. The transmission design is influenced by the position of the engine and driven axle. Overall conversion takes place usually in a manually shifted transmission with variable transmission ratios and in a final drive with a constant transmission ratio. Nowadays, positive-locking transmissions with toothed gears as the most important elements are of even greater significance than non-positive friction-type transmissions.
Two types of toothed-gear transmission are predominant: spur-gear transmissions of the countershaft type as manually shifted transmissions, and planetary-gear transmissions as power-shift transmissions. In addition, transmissions permit the different directions of rotation required for driving forward and backward.
Final drive turns the drive through 90°and reduces the speed of the drive by a set amount to the vehicle.
The differential provides for the equalization of the different axle and wheel speeds when cornering and for uniform distribution of the drive torque.
二.The Hydrodynamic Coupling
1. Hydrodynamic Coupling
Conventionally, the hydrodynamic coupling, also known as the F?tttinger coupling, has an impeller and a turbine wheel with vanes that usually extend in the radial direction. The impeller is often expanded to form a housing which surrounds the turbine. Since, due to the absence of an inner ring, there is no possibility of diverting the oil flow, the turbine torque is equal to the pump torque;
公式
Therefore 公式
The index number depends on the design, the vane angle and the degree of filling of the coupling. The main working area of an hydrodynamic coupling is at v=0.9. 2. Hydrodynamic Converter
The hydrodynamic converter, also known as the Trilok or F?tttinger converter, is capable of operating in two phases: with torque increase in the first phase, and as a hydrodynamic coupling in the second phase. The usual design has three impellers:
1) The pump, which is connected to the engine, acts like a centrifugal pump to produce the flow energy of a fluid. 2) The turbine, which is connected to the transmission input, converts the flow energy back into mechanical energy. 3) The reactor between turbine and pump diverts the flow of the fluid.
Thus, the torque output is higher than the pump torque input from the engine. The torque increaseμμ=Mt/Mp is all the higher, the greater the speed difference (slip）between the pump and turbine. Withυ=0, i.e. with the turbine braked to a standstill (stall point, drive-away point), torque conversion reaches its maximum value and falls virtually linearly with rising turbine speed to a torque ratio of 1:1 at the coupling point. Above the coupling point, the reactor, which is supported on the housing by a one-way clutch, runs, torque-free, in the flow. Thus, the converter is now a clutch without torque conversion.
For automobiles, the vane geometries are such that, at the drive-away point, the maximum torque increase μA is between 2 and 2.5. The hydraulic efficiencyηhydr=υμ is similar in the conversion range to the speed ratioμand reaches values around 97% at high speed.
Fluid couplings form the input element of automatic transmissions (in conjunction with planetary-gear trains, clutches, brakes and one-way clutches) and also of manually shifted transmissions in the form converter and clutch unit. 三．Constant-mesh Transmission
Fig.3-6 illustrates the flow of torque through a typical constant-mesh transmission. This type uses helical or double helical gears which are always in mesh. The mainshaft gear wheels are mounted on bearings and when a gear is required the mainshaft gear is locked to the shaft by a dog clutch.
Although the mechanical efficiency is lower the helical gears are quieter and any damage resulting from a bad gear change occurs to the dog teeth instead of the actual gear teeth.
元素的力量训练
动力传动的要素必须符合下列要求; 1)使开车逃走, 2)把转矩和速度,
3)使不同方向的旋转带动向前和向后, 四)推进传送叶轮力量,
5)允许不同转速时的驱动轮转弯时,
六)保证了优化运行的引擎(或电机)从油耗和尾气排放。
driving-away和电力中断瘫痪,均可能发生后,采用手术离合器赶,离合器滑和桥梁上的差异,发动机转速和权力之间的火车。不同的操作条件的要求改变齿轮,离合器分离的动力列车在转变。
发动机的转矩和转速的传输转换按照tractive-power需求的车辆。传动设计是受的位置和从动轴发动机。整体转换发生通常在手动转向可变传动,传动比例在最后的驱动传动比恒定。如今,positive-locking与齿齿轮变速器作为最重要的成分,更大的意义不可约的磨擦式传输。比
两种类型的toothed-gear传动的优势:spur-gear传输中轴型手动变速器变速箱、planetary-gear转变为某传输。此外,允许不同方向传输所需的旋转驱动向前和向后。
终传动转动90°开车穿过的速度和减少的驱动一定数量在车上。 鉴别提供均衡不同的轴和轮速汽车转向时,为均匀分布和驱动扭矩。 二。水动力耦合 1。水动力耦合
一般来说,水动力耦合,也被称为Fotttinger耦合,方向盘,与叶轮和涡轮叶片,这通常在干熄炉径向方向延伸。叶轮通常是扩大到形成一个住房围绕着涡轮机。因为,由于缺乏一个内圈中,就不可能将油流量、涡轮力矩等于泵扭矩; 公式 因此公式
索引数字取决于设计、叶片角度和充填的耦合程度。主要工作领域是一个水动力耦合v = 0.9。 2。动力转换器
水动力转换器,也被称为Trilok或Fotttinger转换器,可以运行在两个阶段:第一阶段扭矩增加,并作为一个水动力耦合在第二阶段。通常有三个叶轮设计:
1)泵,这是连接到引擎,就像是一个离心泵产生的能量流一种流体。 2)涡轮,这是连接到输入转换传输流的能量带回成机械能。 3)之间的转移和泵涡轮反应器的流动的液体。
因此,扭矩输出高于泵的输入扭矩发动机。扭矩increaseμμ=吨/ Mp是所有的更高,更大的速度差异(滑)之间的水泵和涡轮机。Withυ= 0,例如水轮机刹了车停止(失速点,drive-away点),扭矩转换达到最大值,并且几乎线性上升下降涡轮转速转矩比为1:1的耦合点。以上的耦合点,反应器,在房地产支持由单向离合器,分,torque-free,在流动。因此,转换器现在是一个离合器没有扭矩转换。
为汽车、叶片结构是这样的,在drive-away点,最大扭矩增加μA是2 - 2.5。液压efficiencyηhydr =υμ转换范围是类似的速度达到97%左右ratioμand价值观在高速度。
流体联轴器的元素形成了自动变速器输入(会同planetary-gear火车、离合器、制动器、单向离合器)和手动变速器的形式转移转换器和离合器单位。 三.Constant-mesh传输
阐述了Fig.3-6流量通过一个典型的constant-mesh扭矩传输。这类型使用或双斜齿轮螺旋总是在网格。齿轮主轴轴承,安装在需要时齿轮主轴齿轮锁轴被一只狗离合器。
虽然机械效率低的螺旋齿轮损坏安静些,造成齿轮变化就产生一个坏狗的牙齿代替实际的齿轮。
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