1、 1 TRANSMISSION Of all transmission technologies, the manual gearbox is the most efficient； around 96 per cent of the energy that is put in comes out of the other end. But not everyone can drive one or wants to. Because you have to dip the clutch pedal, it is less comfortable to drive in heavy traff
2、ic. It makes the driver tired and the torque interruptions head-nod effect on passengers can be wearing. The drivers clutch control and corresponding torque interruptions are also the manuals weak point. When accelerating up through the gearbox, each up-shift requires the driver to cut the torque mo
3、mentarily by lifting the gas pedal and dipping the clutch. It may just take a second to complete the operation, but during this time the vehicle is losing speed and acceleration. At the opposite end of the spectrum is the traditional automatic. The modern transmission is by far, the most complicated
4、 mechanical component in todays automobile. It is a type of transmission that shifts itself .A fluid coupling or torque converter is used instead of a manually operated clutch to connect the transmission to the engine. There are two basic types of automatic transmissions based on whether the vehicle
5、 is rear wheel drive . On a rear wheel drive car , the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position . A drive shaft connects the rear of the transmission to the final drive which is located in
6、 the rear axle and is used to send power to the rear wheel. Power flow on this system is simple and straight forward going from the engine, through the torque converter , then through the transmission and driver shaft until it reaches the final driver where it is split and sent to the two rear wheel
7、 . On a front wheel drive car, the transmission is usually combined .With the final drive to from what is called a transaxle. The engine on a front wheel driver car is usually mounted sideways in the car with the transaxle tucked under it on 2 the side of the engine facing the rear of the car. Front
8、 axles are connected directly to the transaxle and provide power to the front wheels. In this example, power flows from the engine through the torque converter to a large chain that sends the power through a 180 degree turn to the transmission that is along side the engine. From there， The power is
9、routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles. There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive
10、all four wheels but the two systems described here are by far the most popular. A must less popular rear drive arrangement has the transmission mounted to the final drive at the rear and is connected by a drive shaft to the torque converter which is still mounted on the engine. This system is found
11、on the new corvette and is used in order to balance the weight evenly between the front and rear wheels for improved performance and handling. Another rear drive system mounts everything, the engine, transmission and final drive in the rear. This rear engine arrangement is popular on the Porsche. Th
12、e modern automatic transmission consists of many components and systems that are designed to work together in a symphony of planetary gear sets, the hydraulic system, seals and gaskets, the torque converter, the governor and the modulator or throttle cable and computer consider being an art form. On
13、 the automobile planet gear mainly uses in two places, one is the driving axle reduction gear, two is the automatic transmission. Very many net friends all want to know that, the planet gear has any function, why automobile must have it . We knew very well the gear major part all rotates the spool t
14、hread fixed gear. For example mechanical type clock and watch, above all gears although all in make the rotation, but their rotation center (with center of a circle position superposition) often installs through the bearing on the cabinet, therefore, their rotating axis all is the relative cabinet f
15、ixed, thus also is called dead axle gear . Has must have surely moves, the corresponding place, some kind of not that manner knows very well is called planet gear the gear, their rotation spool thread is not fixed, but is installs the support which may rotate in (blue color) on 3 (in chart black par
16、t is shell, yellow expression bearing). The planet gear (green) besides can look like the dead axle gear such to revolve own rotating axis (B-B) to rotate, their rotating axis also (is called planet) along with the blue color support to circle other gears the spool thread (A-A) to rotate. Circles on
17、eself spool thread the rotation to be called rotation, circles other gear spool threads the rotation to be called revolution, looks like in solar system planet such, therefore acquires fame. The spool thread fixed gear drive principle is very simple, meshes mutually in a pair in the gear, some gear
18、takes the driving pulley, the power spreads from its there, another gear takes the driven wheel, the power outputs from it toward outside. Also some gears only take the stopover station, at the same time meshes with the driving pulley, one side meshes in addition with the driven wheel, the power pas
19、ses from its there. In contains the planet gear in the gear system, the situation was different. Because has the planet frame, in other words, may have three rotating axes permissions power input/Output, but also may use the coupling or the brake and so on method. in needs time limits axis the rotat
20、ion, is left over two axes to carry on the transmission, as the matter stands, meshes mutually between the gear relations may have the many kinds of combinations: The power from sun gear input, outputs from other sun gear, the planet put through brake mechanism has checked dies； Power from sun gear
21、input, from planet output, moreover a sun gear ecks dies； The power from a planet input, outputs from sun gear, moreover a sun gear checks dies； Two powers separately from two sun gears inputs, after synthesis from planet output； Two powers separately from the planet and sun gear input, after the sy
22、nthesis output from other sun gear； The power from sun gear input, divides two groups outputs from other sun gear and the planet frame； The power from a planet input, divides two groups to output from two sun gears； Its shift quality is good thanks to its torque converter, but efficiency is relatively poor despite recent advances. Because of this, a lot of the current research is trying to find an efficient alternative to the conventional automatic. The main technologies are continuously variable transmissions (CVTs)； dual
