Figure: This is the most original open differential, which is equipped in our car, but it has no limited slip function.
Well, after briefly explaining what a limited slip differential is, it is necessary to know the types of limited slip differential. The common limited slip differential of passenger cars is divided into four types: fixed, torsion, speed and electronic control. The fixed-speed model that first appeared in cars is rare, and the three-speed model has actually been used in a few models, but it has basically disappeared; The fourth electronic control seems to be a trend in the future, and its well-known use models are Subaru's DCCD, Porsche and so on. The two kinds of limited slip differential introduced in this paper belong to the second type, namely torsion type, which is also a common product in the field of daily automobile upgrading. There are two main types of torque limited slip differential, one is grinding disc and the other is mechanical, but their parameters and working modes are quite different.
Figure: This structure is the legendary mechanical limited slip differential. Its scientific name is Torsten limited slip differential. It is characterized by relying on screws to limit slippage, and its limiting degree is expressed by locking rate%.
In fact, many riders have heard of grinding products, that is, the modified products launched by companies with the highest reputation in the modification market, such as Daikin and Cusco, are all grinding products. The grinding wheel L.S.D is more suitable for off-road and intense driving, and its working principle can be divided into three modes: 2way, 1.5way and 1way to adapt to different driving forms. In other words, only abrasive products have several ways. At present, the absolute main product in the original car or modified and upgraded market is not this kind of grinding limited slip differential which is inconvenient to use in daily life and has great noise, but a mechanical product. Tolson limited slip differential was first invented by American Vernon Griessmann. According to the different internal structure, the patent application of Gleasman can be divided into three stages: T 1, T2 and T3. At present, T3 with planetary gear structure is used, which is the most widely used type of limited slip differential. Its characteristics of simple maintenance, no noise and no special oil are more suitable for daily use. Many mass-produced cars have their own TOSON LSD, including Toyota 86, Mustang GT, Megane rs, Peugeot 308GTI, some versions of Mazda RX-8 that entered China earlier, Lexus LC and so on. The original factory has its own TOSON LSD, but the maximum locking rate is lower than that of the modified TOSON mechanical L.S.D, and its function is more about the direction of daily driving safety.
Figure: Torsten limited slip differential is often used in the original car. Besides the differential speed, it will also be used in the four-wheel drive system, such as Audi's Quattro.
I know that the most famous original limited-slip differential or modified limited-slip differential is tolson-type mechanical limited-slip differential, so why is everyone generally talking about mechanical limited-slip differential? In fact, the most important point is that you don't understand the meaning of mechanical differential. In fact, you can understand it with a very simple explanation: the mechanical limited slip differential explains its function through the locking rate (percentage). What is the locking ratio? It means the ratio of the speed difference between two wheels. For example, the locking ratio of this LSD is 70%, which means that the LSD allows the speed difference between the two wheels to be 30%. When the speed difference between the left and right wheels reaches this value, LSD will lock. This locking rate can actually be adjusted, so be sure to explain it to the technicians when installing.
Figure: this is a grinding LSD, and the middle cross shaft pushes the friction plates on both sides to lock by friction.
Figure: Because the differential is realized by moving the cross shaft, in order to better explain when it works, how many ways are used to explain it? 1 means that it works only when stepping on the accelerator; 1.5Way means that stepping on the accelerator will have a slight impact after work; 2Way is to step on the accelerator or put it down.
In foreign automotive aftermarket, the sales of mechanical or grinding LSD are amazing. The biggest reason is that foreign automobile culture has penetrated into the bone marrow. As we all know, safe driving is not based on the assumption that the iron sheet of the vehicle itself is thick enough, but on more active driving control concepts such as tire grip, braking efficiency, transmission accuracy and engine response. This idea is the concept of car use that treats both the symptoms and the root causes. But on the other hand, it is rarely used in China, mainly because everyone doesn't know what LSD is for, and more people think it is used for "racing". Since LSD is so useful, why don't major automobile manufacturers include LSD as standard? To save costs, of course.
Finally, some problems are put forward: the parameters of the grinding disc type L.S.D are 2way, 1.5way, 1way, and the locking rate can be adjusted freely by adjusting the position of the friction plate; The mechanical L.S.D drives the locking change through the wheel speed difference, but there is only a fixed single locking rate data, which cannot be adjusted. Recently known as "mechanical 1.5way" differential, it refers to high-performance mechanical differential, and it is an optimized version different from low-lock LSD. Mechanical type can also bring higher locking rate, and it can catch up with the performance of grinding type in minutes.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.