Reducer of the rear bridge
As is known, modern motor vehicles are driven by an internal combustion engine (ICE). The energy by which the machine is moved is removed from the crankshaft of the internal combustion engine, but is not supplied directly to the driving axle, otherwise the wheels will rotate very quickly and the vehicle will become unmanageable. In order to reduce the speed of rotation of the wheels of the vehicle, the designers use a transmission and a axle reduction gear.
The question arises – what is the gearbox used for? Especially in the front-wheel drive version of the car – turn yourself the transmission of the semi-axle of the wheels, and all cases. Yes, the motor equipment is so arranged, and there is no reduction gear there. But the motorcycle has one driving wheel, and the car has at least two, and they often rotate at different speeds, here there is no way to do without a reduction gear. In addition, it is necessary to distribute rotation from one shaft to two half-axes, which is the work of the reduction gear.
It should be clarified that the “reduction gear” device itself also contains a differential that distributes torque on the output shafts with the required proportion, which means that the reduction gear itself consists of two devices: a reduction gear (reducing the speed of rotation) and a differential (distributing the moment of rotation).
The reduction gear mounted on the rear axle of the machine may have a different gear ratio, which is expressed by the ratio of the speed of the drive shaft to the speed of the driven shafts. Perhaps you have ever heard of a “high-speed bridge” and a “traction bridge.”
The second has a high gear ratio, develops a lower speed, but has an increased load capacity relative to the first bridge of the car as a whole.
In addition to imported commercial minibuses with traction bridges, an example of a domestic VAZ car can be cited. Thus, the jigs with the body “wagon,” designed more for the movement of goods, were equipped with a reduction gear of the rear axle, having the number 4.4, and in the body the sedan is already 4.3. This rule applies to all rear-wheel drive vehicles.
Structural features of reduction gear box
Gear gears are used to transmit torque to driven output shafts from the drive shaft. Since the force is transmitted at 90 degrees, the gears have a conical shape. In addition to specific force transmission, bevel gears have less noise during operation, and this is very important for a passenger car.
In order to reduce the speed of rotation of the output shafts by the reduction gear, it is necessary to observe the rule: the driving gear must be smaller in size than the driven gears. I.e. One 180 degree rotation of the drive shaft shall cause partial rotation of the driven. The speed will be reduced, but the traction force will be increased. In some vehicles, such as cross-country vehicles, the speed slowdown is significant, but it does not allow the cross-country vehicle to be stuck off-road.
To extend the life of the gear box
There are no specific rules for the operation of the reduction gear box. The only thing to pay attention to is the glands of the half-axles, which wear over time and not only release oil from the reduction gear box, but also contribute to the penetration of dirt into the gears, which risks rapid wear. It is necessary to check the places of semi-axles output from time to time for the presence of oil subways.
In addition, the oil in the reduction gear box has a scheduled replacement period. It is necessary to fill the oil of the required specification. This information is usually contained in a book on the operation of your car.
What the reduction gear box housing is made of
Typically, this hull is target metal, giving additional strength to the reducer it needs given its location. Usually its body is cast iron, but at the same time has a large mass. That is why for installation on sports cars the housing is made of light metal, strengthening steel only places subject to heavy loads.
Where the rear axle reduction gear is used
The rear axle reduction gear is equipped with all cars with rear drive, both Russian and imported, all four-wheel drive cars, regardless of the full drive system. At the same time, all four-wheel drive cars have at least two reduction gears – on the front and rear bridges.