A planetary or differential gearbox belongs to the class of mechanical gearboxes. It got its name from the fact that it uses a planetary gear, with the help of which torque is transmitted and converted from the engine through the gearbox to the wheels. There are gearboxes with one or more planetary gears.
Instructions
Step 1
A few words about what a differential is. This is a mechanical device that transmits torque from the gearbox to the independent wheels of the drive axle, but in such a way that the angular speeds of the gearbox and wheels may not coincide with each other, thanks to the planetary mechanism. Almost all off-road vehicles have a differential lock for increased cross-country ability.
Step 2
Basically, the locking mechanism is installed on the cross-axle differential of the rear axle and very rarely on the front axle. The need for blocking is due to the fact that the usual center differential of the rear axle always distributes the same force between the wheels. So, for example, one of the wheels is on ice and the other on the asphalt. In this case, the wheel on the ice, due to the lack of traction, begins to slip, and the differential, for this reason, cannot supply a large force, which automatically affects the left wheel, which receives the same weak force. Thus, there is an equalization of efforts between the wheels, but only in the "weak" side, where the effort is less, that is, in the direction of the skidding wheel.
Step 3
To use a wheel that has strong traction, you need to firmly "tie" the wheels to each other with a lock. There are several ways to block. With the help of a manual differential, it rigidly fixes the clutch connecting the axle shafts or cardan shafts, and gives them the same torque at the same angular velocity. It should be turned on only when the car is stopped, and it should be used only at low speeds off-road.
Step 4
Automatic locking can be carried out using a viscous coupling, which is installed coaxially to the axle shaft. One of its drives is attached to the differential cup, the other to the axle shaft. When the car is moving in normal mode, the angular speeds of rotation of the cup and axle shafts coincide or differ slightly when cornering. When a higher angular speed of rotation occurs on one of the wheels relative to the other, friction arises in the viscous coupling, and it is blocked.
