With the rapid development of technology, there are now more and more gears in transmissions. Ten years ago, most family cars only had a 5-speed or even 4-speed automatic transmission, but now the gearbox has all gone to the top gear. With the development of data, 8AT, 9AT and even 10AT gearboxes have become more common.
So what are the advantages of a gearbox with a large number of gears?Is the more gears the more fuel-efficient?Today we're going to talk about that. The gearbox is the most important component in a gasoline vehicle. Because the engine speed is inherently very fast, it is not possible to connect the engine directly to the propeller shaft.
Therefore, a gearbox is required to connect the two to guarantee a smooth ride of the vehicle. Surgery. Theoretically speaking, the CVT continuously variable transmission is actually the best way to ensure the fuel economy of the vehicle, because after all, the working conditions of the internal combustion engine change with the change of engine speed, and the CVT transmission has the characteristics of "infinite transmission".
Many "gear ratios", so the CVT gearbox can theoretically find the right gear ratio for the current engine operating conditions at any time. However, there is a "flaw" in the CVT gearbox, which is that its internal structure is not rigidly connected. To put it bluntly, the CVT gearbox is "skiddy". As soon as the engine torque is too high, the CVT transmission starts to overwhelm.
How can a multi-speed gearbox reduce the fuel consumption of the car and improve the economy?It is known that the engine has one of the most economical working ranges. Only when the engine is in this speed range can the car have better power and lower fuel consumption. This is clearly seen from the general characteristic curve of the engine.
However, the power of the engine is not transmitted directly to the wheels to drive the car, but is redistributed through the gearbox and then to the wheels. In this way, the role of the gearbox is very important. After it takes over the power of the engine, it shifts into a suitable gear according to the actual needs of the car to amplify or decrease the power of the engine.
The wheels are then driven by a transaxle;At the same time, the resistance on the wheels is fed back to the engine, allowing the engine to run in time. Adjust your working conditions. An excellent gearbox allows the engine to always work in the optimal operating range by switching its own gears, achieving the goal of maximum power and minimum fuel consumption.
Structurally speaking, almost all AT gearbox structures are composed of torque converter planetary gear sets. Whether it is 6AT, 8AT, 9AT or even 10AT, their structures are basically similar. Torque converters are primarily responsible for transmitting power and buffering the speed difference between the gearbox and the engine.
When we hit the brakes in D gear, although we could feel the engine "working hard", it didn't stall. This is where the torque converter comes in. The planetary gear set is responsible for changing the gear ratio. Essentially, it is the use of the natural ratio of teeth between planetary gears to achieve different gear ratios.
A multi-plate clutch is then utilized to secure the sun gear, ring gears and planetary carriers of the planetary gear set. Achieve different speed outputs. In order to achieve more gear ratios, more sets of planetary gear sets need to be integrated. In other words, the biggest difference between 6AT, 8AT, and 9AT is the number of planetary gear sets in series.
Is multi-speed transfer really that good?The more gears, the higher the requirements for gearbox assembly and the machining accuracy of each componentBut most of our vehicles don't need that much gearing. Personally, I think 8AT is enough. If there are too many gears, the transmission will be used less frequently.
Sometimes students who often drive in urban areas use 7th gear. The above is no longer needed. The current Crown Road 9-speed gearbox only shifts to 9th gear when the highway reaches 120kph. Such a design bug is indeed not small, and it is not a pragmatic choice!
To sum up, the above sharing on this topic is my personal opinion and suggestion. I hope this topic I have shared will be helpful to you. I hope you enjoy my sharing. If you have a better analysis on this topic, I hope you can share it. Leave a comment to discuss the topic together.
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