1, a role of transmission
Physical characteristics of the engine determines the presence of transmission. First, any engine has a peak speed; second, engine maximum power and maximum torque occurs at a certain speed range. For example, the engine maximum power at 5500 rpm appear. Transmission can produce different gear ratio between the engine and the wheels in an automobile traveling, the shift may be such that the engine operate at its optimum power performance state. Ideally, the transmission gear ratio should be flexible. The continuously variable transmission (CVT) to have this characteristic, can play a better dynamic performance of the engine.
2, bis, the CVT
The continuously variable transmission has a continuously variable speed ratio. It has been because of price, size and reliability of the car without a lot of equipment. Now, the improved design makes use of a CVT has been more common.
Domestic audi 2.8 CVT
is connected to the gearbox via the clutch to the engine, so that the input shaft of the gearbox and the engine can reach synchronous speed.
C-Class (Gallery) stage Sport Coupe 6-speed manual transmission
to provide a five-speed gearbox five different gear ratio, the rotational speed difference generated between the input shaft and the output shaft.
3, three simple transmission model
To better understand the working principle of the gearbox, let us first look at a simple model 2-speed gearbox and see each how to fit between a portion is:
of the input shaft (green) and is connected to the engine through the clutch, the gear shaft and is a member of the above.
axis and the gear (red), called intermediate shaft, which are rotating together. Axis (green) rotating shaft rotated by the intermediate gear,In this case, the intermediate shaft can be transmitted to the power of the engine.
axis (yellow) is a splined shaft, and the drive shaft is directly connected, through the differential to drive the car. Wheel rotation will rotate together with the spline shaft.
gear (blue) freely rotatable on the spline shaft. The engine is stopped, but the vehicle is still in motion, the gear (blue) and the intermediate shaft in a stationary state, while the spline shaft is still rotating with the wheel.
gear (blue) and the spline shaft are connected by a sleeve, the sleeve can be rotated with the spline shaft, but also can be slidably engaged with a gear (blue) around the spline shaft.
1 Profile
when hanging up a gear, the sleeve and the gear on the right (blue) engages. Shown below:
As shown, the input shaft (green) to drive the intermediate shaft, an intermediate shaft driven gear on the right (blue), are connected through the sleeve gear and the spline shaft, to transfer energy to the drive shaft. At the same time, the left gear (blue) is also rotated, but the absence of the sleeve engages, so it does not affect the spline shaft.
When the sleeve (first shown in FIG.), The transmission is in neutral position when the two intermediate gears. Consisting of two gears are spline shaft rotated by the gear speed (red) between the intermediate shaft and a gear shift (blue) ratio determined.
4. Fourth, the real transmission
Today, the five-speed manual gearbox has been very common application, the following is its model.
of the shift lever are connected by three links the three shift forks, see below
There is a point in the middle of the rotation of the shift lever, the first speed dial when you are, in fact, is the link and shift fork pushed to the opposite direction.
When you move around the shift lever is actually selected shift fork different (different sleeve); is selecting different gear (blue) moves back and forth.
achieved by a reverse idler gear (purple). As shown, a gear (blue) are always (blue) is rotated in the opposite direction to other gear. Thus, in the process of advancing the car, it is impossible to hang into reverse gear, and the gear teeth on the sleeve (Blue) can not be engaged, but will generate a lot of noise.
5, the synchronization means
is such that the synchronization gears and the meshing teeth on the sleeve (blue) to generate a frictional contact before, see below the
gear (blue) just tapered projections snap into the sleeve tapered gap, such that the friction between the sleeve and the gear (blue) synchronization, outside the sliding sleeve, and the gear.
have their own implementations of the car manufacturers manufacture gearboxes, presented here is a fundamental concept!
6, analysis of the advantages and disadvantages of the manual transmission
apparent advantages of simple structure, reliable, inexpensive to manufacture and maintain, and the high transmission efficiency (in theory, would be more fuel-efficient), additionally , because it is purely mechanical control, quick shift reaction, and can be more direct expression of the will of the driver, and therefore richer driving pleasure, these are the advantages of a manual gearbox. But compared to the automatic transmission, it is cumbersome to operate, and frustrated at a distinct disadvantage when the range switching is irreparable.