Torsen Differentials - How They Work and What STaSIS Does to Improve Them For the Audi Quattro One of the best “bang-for-your buck” products that STaSIS has. TORSEN DIFFERENTIAL. This is Documents, PDF file and viewer manuals online in PDF format entitled torsen differential latest out there in ebook wanting wherever it's. Das Torsen-Verteiler-Differential ist eine Neukonstruktion und wird in den neuen Audi 80 quattro und Audi 90 quattro ab Modelljahr '87 eingebaut. Torsen Limited-Slip Differential. Therefore, the Torsen differential will not support any appreciable torque 'wind-up' between the two rear tires during braking. The Torsen differential works just like a conventional differential but can lock up if a torque imbalance occurs. Torsen traction control article (PDF).
Limited- slip differential - Wikipedia, the free encyclopedia. A limited- slip differential is a type of automotive differential gear arrangement that allows for some difference in angular velocity of the output shafts, but imposes a mechanical limit on the disparity. In an automobile, such limited- slip differentials are sometimes used in place of a standard differential, where they convey certain dynamic advantages, at the expense of greater complexity. Early history[edit]In 1. Ferdinand Porsche designed a Grand Prix racing car for the Auto Union company. The high power of the design caused one of the rear wheels to experience excessive wheel spin at any speed up to 1. In 1. 93. 5, Porsche commissioned the engineering firm ZF to design a limited- slip differential to improve performance.[citation needed] The ZF "sliding pins and cams" became available,[1] and one example was the Type B- 7.
Click on the hyperlink s below to retrieve information about the Torsen differential. The hyperlinks are to documents published in Portable Document Format (PDF). Torsen differentials operate in a manner very similar to a Salisbury differential. Usually, the preload term, B, is nearly zero for a Torsen differential. The.
The development of a differential for the improvement of traction Book 1.43 MB | Ebook Pages: 121 SYNOPSIS: An introduction to the function of Gleason's TORSEN.
VWs, although technically this was an automatic locking differential, not a limited- slip. Benefits[edit]The main advantage of a limited- slip differential is demonstrated by considering the case of a standard (or "open") differential in off- roading or snow situations where one wheel begins to slip. In such a case with a standard differential, the slipping or non- contacting wheel will receive the majority of the power (in the form of low- torque, high rpm rotation), while the contacting wheel will remain stationary with respect to the ground. The torque transmitted by an open differential will always be equal at both wheels; if one tire is on a slippery surface, the supplied torque will easily overcome the available traction at a very low number.
A limited-slip differential is a type of automotive differential gear arrangement that allows. the original Torsen differential was used in racing by Mario.
For example, the right tire might begin to spin as soon as 5. Since the same amount of torque is always felt at both wheels, regardless of the speed which they are turning, this means that the wheel with traction cannot receive more than 5. Meanwhile, the tire on the slippery surface will simply spin, absorbing all of the actual power output (which is a function of torque provided over time), even though both wheels are provided the same (very low) amount of torque. In this situation, a limited- slip differential prevents excessive power from being allocated to one wheel, and so keeps both wheels in powered rotation, ensuring that the traction will not be limited to the wheel which can handle the minimum amount of power. The advantages of LSD in high- power, rear wheel drive automobiles were demonstrated during the United States "Muscle- Car" era from the mid 1. It soon became apparent that "Muscle- Cars" with LSD or "posi" (positraction) were at a distinct advantage to their wheel- spinning counterparts.
Basic principle of operation[edit]Automotive limited- slip differentials all contain a few basic elements. First, all have a gear train that, like an open differential, allows the output shafts to spin at different speeds while holding the sum of their speeds proportional to that of the input shaft. Second, all have some sort of mechanism that applies a torque (internal to the differential) that resists the relative motion of the output shafts. In simple terms, this means they have some mechanism which resists a speed difference between the outputs, by creating a resisting torque between either the two outputs, or the outputs and the differential housing.
There are many mechanisms used to create this resisting torque. The type of limited- slip differential typically gets its name from the design of this resisting mechanism. Examples include viscous and clutch- based LSDs. The amount of limiting torque provided by these mechanisms varies by design and is discussed later in the article. A limited- slip differential has a more complex torque- split and should be considered in the case when the outputs are spinning the same speed and when spinning at different speeds.
The torque difference between the two axles is called Trq d .[2] (In this work it is called Trq f for torque friction[3]). Trq d is the difference in torque delivered to the left and right wheel. The magnitude of Trq d comes from the slip- limiting mechanism in the differential and may be a function of input torque (as in the case of a gear differential), or the difference in the output speeds (as in the case of a viscous differential). The torque delivered to the outputs is: Trq 1 = ½ Trq in + ½ Trq d for the slower output. Trq 2 = ½ Trq in – ½ Trq d for the faster output.
When traveling in a straight line, where one wheel starts to slip (and spin faster than the wheel with traction), torque is reduced to the slipping wheel (Trq 2 ) and provided to the slower wheel (Trq 1 ). In the case when the vehicle is turning and neither wheel is slipping, the inside wheel will be turning slower than the outside wheel. In this case the inside wheel will receive more torque than the outside wheel, which can result in understeer.[3]When both wheels are spinning at the same speed, the torque distribution to each wheel is: Trq (1 or 2) = ВЅ Trq in В±(ВЅ Trq d ) while. Trq 1 +Trq 2 =Trq in . This means the maximum torque to either wheel is statically indeterminate but is in the range of ВЅ Trq in В±( ВЅ Trq d ). Several types of LSD are commonly used on passenger cars.
Fixed value. Torque sensitive. Speed sensitive. Electronically controlled. Fixed value[edit]In this differential the maximum torque difference between the two outputs, Trq d , is a fixed value at all times regardless of torque input to the differential or speed difference between the two outputs. Typically this differential used spring- loaded clutch assemblies. Torque sensitivity (HLSD)[edit]This type includes helical gear limited- slip differentials and clutch, cone (an alternative type of clutch) where the engagement force of the clutch is a function of the input torque applied to the differential (as the engine applies more torque the clutches grip harder and Trq d increases). ZF LSD – clutch stack visible on left. ZF LSD – spider pinion shaft ramps visible.
Torque sensing LSDs respond to driveshaft torque, so that the more driveshaft input torque present, the harder the clutches, cones or gears are pressed together, and thus the more closely the drive wheels are coupled to each other. Some include spring loading to provide some small torque so that with little or no input torque (trailing throttle/gearbox in neutral/main clutch depressed) the drive wheels are minimally coupled. The amount of preload (hence static coupling) on the clutches or cones are affected by the general condition (wear) and by how tightly they are loaded. Clutch, cone- type, or plate LSD[edit]The clutch type has a stack of thin clutch- discs, half of which are coupled to one of the drive shafts, the other half of which are coupled to the spider gear carrier. The clutch stacks may be present on both drive shafts, or on only one. If on only one, the remaining drive shaft is linked to the clutched drive shaft through the spider gears.
In a cone type the clutches are replaced by a pair of cones which are pressed together achieving the same effect. One method for creating the clamping force is the use of a cam- ramp assembly such as used in a Salisbury/ramp style LSD. The spider gears mount on the pinion cross shaft which rests in angled cutouts forming cammed ramps.
The cammed ramps are not necessarily symmetrical. If the ramps are symmetrical, the LSD is 2 way. If they are saw toothed (i.
LSD is 1 way. If both sides are sloped, but are asymmetric, the LSD is 1. See the discussion of 2, 1. An alternative is to use the natural separation force of the gear teeth to load the clutch. An example is the center differential of the 2. Audi Quattro RS 5.[4]As the input torque of the driveshaft tries to turn the differential center, internal pressure rings (adjoining the clutch stack) are forced sideways by the pinion cross shaft trying to climb the ramp, which compresses the clutch stack.
The more the clutch stack is compressed, the more coupled the wheels are. The mating of the vertical ramp (8.
В° in practice to avoid chipping) surfaces in a one- way LSD on overrun produces no cam effect or corresponding clutch stack compression. Way, 1- way, 1. 5- Way[edit]Broadly speaking, there are three input torque states: load, no load, and over run. During load conditions, as previously stated, the coupling is proportional to the input torque. With no load, the coupling is reduced to the static coupling. The behavior on over run (particularly sudden throttle release) determines whether the LSD is 1 way, 1. A 2- way differential will have the same limiting torque Trq d in both the forward and reverse directions. This means the differential will provide some level of limiting under engine braking.
A 1- way differential will provide its limiting action in only one direction. When torque is applied in the opposite direction it behaves like an open differential. In the case of a FWD car it is argued to be safer than a 2- way differential.[5] The argument is if there is no additional coupling on over run, i. LSD as soon as the driver lifts the throttle, the LSD unlocks and behaves somewhat like a conventional open differential.
This is also the best for FWD cars, as it allows the car to turn in on throttle release, instead of ploughing forward.[5]A 1. Trq d_fwd, d_rev , are different but neither is zero as in the case of the 1- way LSD. This type of differential is common in racing cars where a strong limiting torque can aid stability under engine braking. Geared LSD[edit]Geared, torque- sensitive mechanical limited- slip differentials use worm gears and spur gears to distribute and differentiate input power between two drive wheels or front and back axles. This is a completely separate design from the most common beveled spider gear designs seen in most automotive applications.
As torque is applied to the gears, they are pushed against the walls of the differential housing, creating friction.
Torsen Limited- Slip Differential. The Torsen is the ultimate performance differential. Combine a well balanced suspension package on your Mustang with a Torsen for incredible traction!
The Torsen's unique torque- sensing ability keeps engine power going to the ground during changing traction conditions. The Torsen functions as an open differential as long as the amount of torque transmitted to each rear wheel remains equal. When one tire begins to lose traction, the Torsen instantly senses the change in torque being applied to the ground. The excess torque that cannot be delivered to the ground by the tire that is beginning to lose traction is delivered to the opposite tire, which has better traction and can take more torque. The Torque Bias Ratio (TBR) is the ratio indicating how much more torque the Torsen can send to the tire with more available traction, than is used by the tire with less traction.
This ratio represents the "locking effect" of the differential. The 4: 1 TBR of the Torsen T- 2. R means that this differential is capable of delivering up to four times as much torque to the tire with better traction than is delivered to the tire with the least available traction. By comparison, the Torsen T- 2.
R can deliver about 2. During braking there is little or no torque being conveyed to the differential, and so there is little or no torque difference between the two rear tires. Therefore, the Torsen differential will not support any appreciable torque "wind- up" between the two rear tires during braking. Because of this, the Torsen differential does not interfere with the functioning of anti- lock brake systems. The clutch plates of the Mustang's stock Traction- Lock differential wear out, requiring periodic replacement to maintain its functionality. This wear causes axle endplay on a solid axle car, which in turn increases brake pad kickback.
Axle endplay does not increase over time with a Torsen differential because it does not have clutch plates to wear out. This makes the Torsen differential ideal for use with fixed- mount brake calipers. While it is ideal for street use, autocrossing, and road racing, the Torsen differential is not recommended for drag strip use. The Torsen differentials fit Mustang 8. IRS, and are available in 2.