These gearboxes, which are both automatic gear trucks, are very different.

[Original Truck House] If you know something about cars, the automatic names such as AMT, AT, CVT and DCT will be quite familiar. In today’s truck circle, automatic transmission is becoming more and more popular, and AMT is the most used one.

Recently, it has been reported that the AT that Sinotruk will possibly install has attracted the attention of many card friends. So what’s the difference between this AT and AMT? Let’s talk to you about several automatic transmission types of heavy-duty vehicles.

These gearboxes, which are both automatic gear trucks, are very different. TraXon

AMT is the absolute mainstream of automatic transmission on freight trucks, such as I-Shift, PowerShift and TraXon, a new generation automatic gearbox of ZF.

These gearboxes, which are both automatic gear trucks, are very different. AMT stop lever

Although both are automatic gears, we are used to distinguishing AMT from general automatic transmission. From the mechanical structure, AMT is the same as manual gearbox, except that it replaces manual gear shifting with electronic control system.

These gearboxes, which are both automatic gear trucks, are very different.

Liberating AMT and Using Bosch Electronic Control System

Due to the structural characteristics, it has almost the same transmission efficiency, torsional strength and durability as the manual gearbox. Therefore, we can also see that domestic manufacturers have introduced their own AMT on the basis of the original manual gearbox and an electronic control system.

When we generally talk about AT, we usually refer to this gearbox with only one main shaft and all planetary gear sets. Unlike MT and AMT, which use constant meshing gears with fixed shafts, AT uses planetary gear mechanisms that cooperate with multiple sets of clutches to realize speed change.

These gearboxes, which are both automatic gear trucks, are very different. Allison 4500, 6th gear AT

There are different types of planetary gears, such as Simpson type, Ravinelhe type, etc., and their structures are quite complicated. We can understand how a single planetary gear set realizes speed change from its work.

These gearboxes, which are both automatic gear trucks, are very different.

The planetary gear mechanism has three moving parts that can rotate relatively: the sun gear, the planet carrier (the part connecting multiple planetary gears) and the outer gear ring. By locking one of the components and making the other two active inputs and passive outputs, many different speed ratios can be realized. For example, the following four gears are realized:

1. Low gear: sun gear takes the initiative, the planetary carrier is passive, and the gear ring does not move;

2. Middle gear: sun gear does not move, the planetary carrier is passive, and the gear ring is active;

3. High gear: sun gear does not move, the planetary carrier is active, and the gear ring is passive;

4. Reverse gear: sun gear takes the initiative, the planet carrier does not move, and the gear ring is passive.

These gearboxes, which are both automatic gear trucks, are very different.

△ sun gear does not move

Although this kind of gearbox is quite common in passenger cars, it is rarely used for cargo purposes because of its complex structure and limited number of gears. Heavy AT generally has only 6 or 7 gears, and its transmission efficiency is low.

These gearboxes, which are both automatic gear trucks, are very different. Allison 4700 automatic transmission is used in Shaanxi Automobile’s big car.

But because of its natural combination with hydraulic torque converter, it is also used in super-heavy vehicles, such as mine cars, large transport vehicles and so on. (The main function of hydraulic torque converter is to cushion the impact of huge power connection, which is impossible for general clutches.)

At this year’s Shanghai Auto Show, Allison released a specially designed 10-speed automatic gearbox named TC10, which will probably be equipped in the future.

These gearboxes, which are both automatic gear trucks, are very different. Allison TC10 automatic gearbox

As far as I know, Allison’s most commonly used automatic gearbox names in the past are all pure digital series, from 1000 series to, for example, the current mine car usually uses Allison 4000 series.

In the model TC10, TC refers to the torque converter, and 10 is the number of gears. It is distinguished from Allison’s general AT model in naming, and it is also completely different in structure. It is like a combination of AT and MT.

These gearboxes, which are both automatic gear trucks, are very different.

Like the general AT, TC10 also has a hydraulic torque converter, but after the torque converter is a three-axis structure very similar to manual transmission and AMT. Different from AMT, we can see that there is a multi-disc clutch on the intermediate shaft, which should be an electronically controlled shift mechanism.

These gearboxes, which are both automatic gear trucks, are very different.

Further along the output shaft, TC10 also has a combination of multi-disc clutch and planetary gear mechanism like AT, where further speed change function can be realized. Therefore, this part, as a special auxiliary box, has expanded the gear shift, so it has a 10-speed shift and a more compact structure.

It is still too early to talk about such a new type of gearbox, such as its application scope, use effect, durability and so on. However, AMT has become the mainstream automatic transmission type of tractor. Can other forms of automatic transmission break this rule? (Text/Li Wenhao)

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