An automotive gearbox is a bevel gear transmission designed to distribute and increase the torque transmitted from the engine shaft. In front- and rear-wheel drive cars, one gearbox is installed on the drive axle, and all-wheel drive cars have 2 gearboxes, which ensure the transmission of torque to each pair of wheels.
A gearbox in a car is necessary to distribute the torque transmitted from the engine between the drive wheels. Structurally, the automotive gearbox is a bevel gear located in a separate housing.
Depending on the type of car, the gearbox is located on the front or rear axle, and the four-wheel drive assumes the presence of two gearboxes, since the torque in this case is distributed between all wheels.
Gear Ratio of Automotive Gearbox
The main characteristic of a gearbox, like any other mechanical transmission, is the gear ratio, which shows the degree of decrease in the angular speed and increase in the torque transmitted to the wheels. The gear ratio directly depends on the number of teeth of the driving and driven gears. In gearboxes, the driven gear always has a larger number of teeth. Due to their good performance, gears with circular teeth are widely used in automobile gearboxes.
The gear ratio close to one has the gearboxes of high-speed cars, in which the number of teeth of the driven gear is only a few units more than the leading one. The increase in the gear ratio increases the traction characteristics of the vehicle, which is especially important for special vehicles and tractors.
Features of the installation of gearboxes on all-wheel drive vehicles
Gearboxes with the same gear ratio must be installed on the front and rear axles of all-wheel drive vehicles, since otherwise it becomes impossible to operate the machine when the center differential lock is engaged.
Gearbox failures and repairs
Lubrication of rotating parts in the engagement zone is of great importance for ensuring the reliability of the vehicle gearbox. Leakage of lubricant can lead to oil starvation, as a result of which the gear teeth will overheat and wear intensively. Periodic control of the transmission condition, carried out by professional service station employees, will help to avoid breakdowns.
Repair of the gearbox is a work of particular complexity, since it involves a large number of adjustments and subsequent tests. One of the gears of the gearbox cannot be replaced without selection and running-in, since otherwise the required area of the contact patch will not be provided. The gearbox is adjusted by changing the gap between the end of the gear wheel and the unit body.
