1. the LSD LSD
limited slip differential, the English called Limited Slip Diff, referred to the LSD. Limited slip differential, by definition is modified to limit a differential wheel slip, it means both the drive wheel rotational speed difference is allowed within a certain range in order to ensure the normal type differential curve traveling performance and the like.
ordinary differential function principle:
turned to the current design of the vehicle is based on the Ackerman principle to set the fifth round, which is within the curve of the steering wheel an angle greater than the outer wheel. Then the trigonometric function calculated by the rotation of the inner wheel will be shorter than the distance from the outside of the wheel, as soon as there are differences from the equal inner and outer wheel (left and right wheel) rotational speed is inconsistent, if the transmission output from the propeller shaft by no difference speed detector to separate the left and right outputs, then the vehicle can not adjust the left and right wheel speed when cornering. When the slow and not by excess friction when to take over, the curve will be cornering at high speed due to the extra wheel rotation and friction, causing the tire to jump off the ground using the joint axle and the vehicle body hanger up occurs when the inner body plus the centrifugal force driven up, it is natural turning direction toward the other side capsized.
so that the left and right wheels of the vehicle is definitely not a coaxial type, especially in the design of modern front-wheel drive car again the majority, there is no differential structure, the driver can not control the steering wheel, as long as the driver turns the steering wheel force feedback tires produced by the ground, strong push back the steering wheel center origin, result manipulation can not exist, so the differential is placed in the center of the drive wheel drivetrain essential elements.
Since the bowl by the differential gear is a gear and angle drive, an internal gear, and a differential side comprising the pinion. When the vehicle is straight, there is no differential action, the differential side gears and pinion gear as a whole will not revolving basin gear differential action, as soon as the vehicle turns, the resistance is not the same outer wheel, the differential gear sets by the action of drag force generating rotation function and then adjust the left,Right wheel speed. Since the left and right wheel speed of change and adjustment by the tire and the ground impedance to generate free, so subsequent usage will not cause a vehicle traveling state.
instance when the vehicle fell into a pothole, the wheel would have no any friction at all, the ground wheels relative there is a huge resistance, this time the role of differential will make all the power back the low friction wheel. Will fall into the pit wheel kept turning, and landing gear but no action completely, so the wheels can not travel.
There is also a phenomenon belonging to the tracking condition, the output performance of the so-called phenomenon that when cornering the wheels Bigfoot throttle, particularly evident in the power output, the output torque plus a centrifugal force forcing the vehicle wheel Y since leaving the ground or generate slippage, if there is an idle, it has the power to idle pulley transmission (because of less resistance), the vehicle still can not accelerate progress. When
Another driving mode belonging to intense exercise slipping generated, this phenomenon is neither turning the vehicle, nor left and right wheels disposed in different conditions of the road surface friction coefficient, that is, during acceleration hundred and four huge power output, with the difference in right and left drive shaft length and tire a little inconsistent, resulting in instantaneous power exports to the friction of a weak, non-stop round began to idle, unable to play another round, Of course, the vehicle can not move forward. In order to address these phenomena, so that more of the average power delivered to the left and two on the right wheel, limiting the differential left and right sliding rate proportional to accomplish this goal, the limited-slip differential is the solution to the problem standard parts.
Differential good solution when the car left and right rough road driving and steering wheel rotation speed different requirements; however, the attendant is present so that the differential side wheels when a vehicle skidding power can not be effectively transmitted, i.e. the slipping wheel can not generate a driving force without slipping wheel and no sufficient torque. Our car designers have been working hard, so differential lock appeared. Differential lock a good solution to the problem of the power transmission side of the car occur when wheel slip, i.e. locking differential, so that a differential is no longer active on both sides of the left and right drive wheels can obtain the same torque . But the problem of human nature always give a never-ending process. Meanwhile differential lock and then solve the original problem has brought new problems. This differential lock only applies to the use of off-road vehicles, oppositionThe outer non-paved road, road adhesion is small, even if some of wheel slip occurs when the differential lock does not matter, at least not security issues. But when about friction imbalances appear on a paved good road, due to the friction of the tire and the dry ground is quite large, high-speed turns when the differential lock is very dangerous, because the extra round in the corners of the rotation and friction , causing the tire to jump off the ground using the joint axle and the vehicle body hanger up, when the inside of the vehicle body together with the centrifugal force driving upward, toward the other side it is natural rollover turning direction.
Species:
Torque-sensing the LSD :
is the use of a helical gear set, as the use of the left and right two-group defined slip friction effect, since the transverse and longitudinal helical gear mining gear base interleaving lossless clutch plates, used in rear-wheel drive vehicle, low failure rate, easy maintenance and also tends to be, although the power the output side failed to have a strong performance, but practical principles of its biggest advantages. It is a common differential gear change from the worm gear, and the mounting position and the same form, by means of self-locking worm drive feature (torque can be transmitted to the worm wheel of the worm, the worm wheel and the torque applied to the worm shaft when torque greater than the friction force between the transmitted, but not the rotation) to achieve anti-slip function. The famous Audi quattro is using this structure, there are many high-performance vehicles are based on the original of this type, like the original RX-7 FD3S LSD is quite famous. LSD torque characteristic of the induction type, although it uses less used in the movement, but with the mechanical friction portion better comparison, and the maintenance is very simple, which is its biggest advantage.
LSD helical gears :
still use the internal helical gear configuration, different from the LSD torque inductive gears is helical gears configured this LSD are all ” laterally “, i.e. in the same direction of the output shaft and operation, the size of the planetary gear speed reduction ratio reaches functional features, its biggest weakness is defined minor proportion locking torque slip, but also because no special maintenance and use of maintenance attention, but do not need to use special oil LSD, so as original Honda 1.8 liter Type-R, Silvia S15hellIP; et newer front wheel drive car, almost all of this type of LSD, LSD there is such a phenomenon that the higher the vehicle roof, rotation of the driven left and right wheels, and does not move forward or backward together, Therefore, in the year TIS 1: 9 Touring car specification vehicle inspection process, it can be mixed cross the border secretly alter hiding weapons! LSD inside the helical gear configuration with torque induction LSD somewhat similar, the same ordinary differential spur gear change from helical teeth, but instead of using two different friction, but to change the mounting position of the gear and forms, by installing only the position and form of the helical gear can be achieved by limiting the reduction gear ratio of the left and right drive wheel rotational speed difference. This LSD maximum attainable difference in rotational speed is relatively small. Further, torque induction type gear arranged longitudinally, and such lateral helical gear device, compared with LSD. And a mechanical LSD compared to its biggest weakness is less restrictive locking torque range, but nothing special trouble is not on the maintenance and use.
Lock balls LSD :
The special features of this design, when the small ball is moved in a curved groove, the cut groove of the drum starts actuated play limited-slip effect, especially its general principles and actuation products is very different, currently not considered mainstream products. In terms of ball locking feature of LSD because its structure is quite special, so you can play a very sleek effect, in turn, said that this LSD is not suitable for people in the street like a hurricane, and the last differential may deadlock and play maximum torque, it is worth the sum of the note, the most suitable for the race against the clock occasions.
Mechanical LSD:
In modified vehicles the most traditional and most commonly used, and therefore regarded as the highest visibility of LSD, since the left and right two clutch plates and the pressure plate group, hence referred to as a multi-plate multi-disc clutch LSD, this may be the type of LSD by the clutch plate and the pressure plate are arranged in combination to achieve the function of a limited slip percentage, the percentage of capacity from 25 to 90 percent completion can be. But the only drawback is difficult to take care of, it is important to use LSD special oil to regular maintenance, long driving or vigorous exercise may need to be replaced repair kit. When the clutch plate assembly into poor or Run in the wrong way, can easily lead to different tone curveOr damage to the clutch plate phenomenon. Mechanical LSD fast response, high sensitivity, a limited slip ratio can be realized according to different combinations of pressure plate and clutch plate, a wide tuning range, but the high cost, good durability, when the clutch plate wear, often occur ldquo; Ga ! Ga! rdquo; noise, it is necessary to do regular maintenance, which is also one of its drawbacks.
Active LSD:
is a combination of general LSD from the cam gear, and by a mechanical structure using a spherical groove, to accept passively actuated , the differential means in the new high-tech vehicles, since the hydraulic pressure and equipped with an electronic control system, it is possible to make the active LSD actuation.