Torsen is a trade mark of the JTEKT Corporation. The Torsen differential has many patented components and, is the most unique and ingenious method of providing differential action while overcoming the traction difference problem. This article gives a logical introduction to the working of Torsen differential.
A detailed webpage version of the video is given below.
The internal components
The internal components of a Torsen are quite different from that of a conventional differential. An exploded view of the Torsen is given in Fig.1.
The Vehicle Moves Straight
When the vehicle moves straight, the worm wheels will push and turn the worm gears. So both the drive wheels will rotate at the same speed. Please note here that, in this condition the worm wheels do not spin on its own axis. In this condition, the whole mechanism moves as a single solid unit.
The vehicle takes a right turn
When the vehicle is negotiating a right turn, the left wheel needs to rotate at a higher speed than the right wheel. This fact is clear from the Fig.6.
The worm gear of the faster left axle will make the corresponding worm wheel spin on its own axis. On the other side, relative to the case the slow right axle is turning in the opposite direction; thus the right worm wheel will spin in the opposite direction. The meshing spur gears at the ends of worm wheel will make sure that, the worm wheels are spinning at the same speed. Thus it guarantees a perfect differential action. Perfect differential action implies equal amount of speed loss and speed gain to the right and left wheels. With the perfect differential the vehiclce will be able to negotiate a smooth turn.
Overcoming the Traction difference problem
Now let’s try to understand how the Torsen overcomes the drive wheel traction difference problem. As you might be aware, when your vehicle encounters a situation as shown, the slippery wheel starts to spin very rapidly and will draw the majority of the engine’s power. As a result, the vehicle will get stuck.
Pros and Cons of Torsen
If you are familiar with the other common technologies used to overcome the traction difference problem, you might have noticed a great advantage of the Torsen. While the other technologies allow the drive wheel to slip for a limited amount of time before it gets locked, in Torsen the locking action is instantaneous. That means as soon as the vehicle encounters a traction difference track the wheels will get locked. They are also compact compared to their counter parts.
Following are the some disadvantages of the Toresn type (T1) explained here.
- More difficult to assemble