1, constituting
Differential
by the ordinary differential planetary gear, the planet wheel carrier (differential case), the side gears and other parts. The power of the engine through the shaft into the differential directly drives the planet gear carrier, and then drive the left and right by the two planetary gear axle, drive the left and right wheels. To meet design requirements 🙁 differential speed left axle) + (right axle speed) = 2 (the rotational speed of the planetary carrier).
When the vehicle straight ahead, right and left wheels and the planet carrier rotational speed equal to three in equilibrium, whereas when the vehicle is turning three equilibrium is destroyed, resulting in reduced speed of the inner wheel, the rotational speed of the outside wheel increase.
2. Function
car wheel when negotiating a curve trajectory of a circular arc, if the car turns left, the center point of the arc on the left, at the same time, the right wheels go longer arc than the left wheels, in order to balance this difference, we should slow down a bit to the left wheel and right wheel a little faster, with a different speed to compensate for the difference in the distance.
If the rear wheel shaft formed integrally, can not be done on both sides of the wheel speed difference, i.e. can not be adjusted automatically. To solve this problem, as early as a hundred years ago, the founder of the French car company Renault Louis Renault designed a differential on this stuff.
3, Principle
FIG differential mechanism Such adjustment is automatic differential relates here to the “principle of minimum energy”, i.e. the earth All objects tend minimal energy state. For example, to a bean into a bowl, beans will automatically remain in the bottom of the bowl and never stay in the bowl wall, because the bowl is the lowest potential energy (potential energy), which automatically selects the rest (minimum kinetic energy) without We will be in constant motion. Similarly, the wheel will automatically tend lowest energy state during turning, automatically adjusted according to the turning radius of the left and right wheelsSpeed.
When cornering, since the outer wheel slip has drag phenomenon, the inner wheel has a slip phenomenon, two wheels at this time will generate additional force opposing two directions, due to the “principle of minimum energy” bound leading to different speeds of the wheels on both sides, thereby destroying the balance of the three, and reflected by the axle to the side gear, the rotation force generated planetary gear, speed up the rotation speed of the outer axle, the inner axle speed slows down, in order to achieve both sides wheel rotation speed difference.
If the drive-wheel drive axle on both sides of a shaft rigidly connected with integrin, the only two at the same angular velocity. Thus, when the steering speed, the distance moved is large because the outside wheel than the inner wheel, the outside wheel will slip drag generated while rolling, the inner wheel slip is generated while scrolling. Even the car is traveling straight, also due to uneven road or a flat road, but while the tire rolling radius ranging (tire manufacturing tolerances, wear of different, unequal pressure Loaded unevenness) caused by wheel slip. When
not only increased wheel slip tire wear, increased fuel consumption, and power, but also the steering difficulties, poor braking performance. To make possible wheel does not slip, must ensure that the structure of each vehicle can be rotated at different angular speeds.
inter-axle differential: Generally the driven wheel bearing mandrel, so that it can at any angular speed and the drive wheels are rigidly connected to the two half shafts in with a differential between the two axle. This differential is also called an axis between differential.
The multi-axis drive off-road vehicle, each axle is capable of rotating at different angular velocities, the bridges in order to eliminate sliding wheels, some with two inter-axle differential between the axle.
4, the role of
automotive differential has three main functions, first the output power of the engine is transmitted to the wheel: Next, the final drive torque has been increased bisecting assigned to the two left and right axle; and finally, as the car main reduction gear, the power transmitted to the front wheel will cut down the rotational speed of the drive train, the power to the wheels, while allowing the wheels to rotate at different sides of the wheel speed.
5, Category
Mechanical locking differentials in modern automobiles typically differential operational characteristics into their differential gear and two slip differential class.
1, differential gear : When the rotational speed difference between the left and right drive wheels is present, the drive wheel torque differential slow turn assigned to the drive wheel torque is greater than the fast forwarding. This differential torque split to meet the characteristics of a normal car driving on good roads. But when the car while driving on the way bad, but seriously affected by capacity. For example, when a wheel of the car stuck in the mud road, while the other wheel on the good road, the car often can not move forward (commonly known as slip). At this time, the drive wheels in situ on the muddy road slip, the wheel on the road has good stationary. This is because the smaller the adhesion between the wheel and the road surface on a muddy road, a road surface only through a small reaction torque round of side effect, and therefore the torque distributed to the differential is small round, Although other drive wheel with good adhesion between the road surface is large, but the average distribution of torque characteristics, so that the drive wheel can only be assigned with the same amount of drive wheel slip torque, so that the driving force is insufficient to overcome the running resistance, car can not move forward, and the power is consumed by the drive wheels slip. At this point throttle not only can not make the car go forward, but a waste of fuel, accelerated engine wear, especially the tire wear increased. Effective solution is: dig up the mud in the wheel slip or in the current round of underlying dry soil, gravel, twigs, hay and so on.
2, slip differential : In order to improve vehicle capacity in a bad way, some off-road vehicles and limousines slip differential device on. Characteristics slip differential, when the wheels slip on the bad side of the road, transmits the torque to allow most or all of the wheels on a good road, to take full advantage of the drive wheels to produce adhesion sufficient driving force, making the car a smooth start or continue driving.
6, Torsen LSD system
differential
Speaking AWD sedan, powered system that people can not help but think of the Audi Quattro, Audi’s bold and innovative and it is duty-bound that makes driving more and more people enjoy the AWD brought fun, while the core of the Audi Quattro AWD system is the Torsen LSD differential, who would have thought electronic components rampant today it maintains pure machinery.
Each car must be provided with a differential, ordinary differential action we know: First, it is a set of reduction gears, so that the conversion from the high speed to the normal speed of the transmission output; the first Second, left and right drive wheels can be made at different speeds, i.e. at different speeds of the output curve outer wheel in order to maintain balance. Its drawback is that when passing through slippery roads will be slippery due to loss of traction. And if the increase in limited-slip differential function to be able to meet the car has good handling demand in the bad road, this is the limited slip differential (Limited Slip Differential, referred to as LSD). The basic configuration AWD all-wheel drive system is a car with three differentials, which control the front wheel, rear wheel, the front and rear drive torque distribution. This is not just 3 differential differential simple common people, they are LSD differential, with self-locking function to ensure that slippage occurs slippery road tire wheel always maintain adequate torque output so bad good road handling. LSD differential in the world there are several forms, today we take a look Torsen self-locking differential system.
Torsen origin of the name is taken from the Torque-sensing Traction– feel torque traction, even brand names are from the traction control can be accomplished, professional enough of it!
The core is the Torsen worm, a worm gear system
From a structural view of a Torsen differential, we can see the double-worm, the worm structure thereof is engaged with each other and the configuration of the torque interlock unidirectionally transmitted from the worm wheel to the worm gear differential locking function is achieved, it is this characteristic limits the slide.
When there is no wheel spin traveling on a curve, the front, rear differential effect of the conventional differential, a worm gear does not affect the output speed of the axle shaft different. As the car turn left, rightFaster than the differential side wheel, the left low speed, different speeds about the worm wheel can be closely match the synchronization gear. At this time, the worm and not locked, since the torque from the worm to the worm gear.
When the right wheel slip, the worm components play a role in the case of conventional differential power will not be transmitted to the left wheel. For differential Torsen LSD, the right axle case rapidly rotating worm drive right and left driven by a worm gear synchronization, this time worm characteristics play a role. When the worm gear worm drive, they will lock, left and right worm worm interlocking, to ensure that the non-slipping wheel with sufficient traction.
Characteristics
the Torsen differential
the Torsen differential is a constant-time 4WD, the traction is assigned to each wheel, so there is a good curve, a straight line ( wet / dry) drivability. Self-locking Torsen center differential to ensure a uniform power distribution front and rear wheels. Any different speeds, such as when the front wheels encounter ice, the system will respond quickly, the steering torque is 75 percent slower speed of the wheel, i.e. where the rear wheel. When
Torsen differential to achieve a constant, continuous torque control and management, which continue to work, there is no time delay, without intervention to adjust the total torque output, there would be no significant loss of torque and traction control and vehicle stability control system more advantageous compared. Because there is no tradition of the multi-plate clutch is equipped with self-locking differential, there is also no wear and maintenance free. Purely mechanical LSD has a good reliability.
Differential
to match the Torsen differential may be implemented with any transmission, splitter, other vehicle safety control system with ABS, TCS (Traction Control Systems, traction control) , SCS (stability control Systems, vehicle stability control) compatible. Torsen differential is purely mechanical structure, the wheel slip just a momentary action occurs, the lock having a linear characteristic, the real four-wheel drive is constant, the torque distribution before and during normal driving is usually 50:50. The disadvantage is that it’s very expensive.
Torsen differentialAlready produced to the third generation
Torsen i.e. generation 3rd generation T-3 is an ideal central differential differential. T-3 is still in the outer ring of the planetary gear worm gear, but it is more compact, but also the appearance of a smaller size, under normal conditions the torque distribution is 50:50, the front and rear torque distribution from the T-3 65:35 linear assignment to 35:65. T-3-bis differential system may provide a direct front left, front right, rear wheel torque output to 3, it is adapted to precursors based AWD vehicles.
as the most important four-wheel drive car manufacturer Audi has been to stick with Torsen differential. Now use the Torsen differential for AWD models more and more companies, Ford, General Motors, Audi, Toyota and Volkswagen and other companies. In this electronic age of today, it’s purely mechanical system to securely maintain the reliability and unique position.
7, the clutch manipulation member to the differential would affect
is reasonable clutch actuating member of the differential of the drive system is mainly affected by the impact force member has a great influence. Due to improper operation of the clutch caused by damage to the differential member is common.
power of the engine is transmitted to the two wheels via the transmission, the load on the drive member is great. And the more behind the transmission member by the greater torque, plus up various conditions affect the car, the rear axle differential and axle portion rupture occurs when excessive operating a clutch, a small fire broke character wheel teeth , chrysanthemum small teeth of the side gears and the cross shaft can damage the other member.