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How Diff\'s work. (VERY LONG)

I was up, so I decided to put down everything I know about differentials. I took a lot of time, so I hope I don't come off as some kind of smart-ass.



Car wheels spin at different speeds, especially when turning. The inside wheels travel a shorter distance than the outside wheels. Since speed is equal to the distance traveled divided by the time it takes to go that distance, the wheels that travel a shorter distance travel at a lower speed. Also note that the front wheels travel a different distance than the rear wheels. For the non-driven wheels on your car...the front wheels on a rear-wheel drive car, the back wheels on a front-wheel drive car...this is not an issue. There is no connection between them, so they spin independently. But the driven wheels are linked together so that a single engine and transmission can turn both wheels. If your car did not have a differential, the wheels would have to be locked together, forced to spin at the same speed. This would make turning difficult and hard on your car: For the car to be able to turn, one tire would have to slip. With modern tires and concrete roads, a great deal of force is required to make a tire slip. That force would have to be transmitted through the axle from one wheel to another, putting a heavy strain on the axle components.
The differential is a device that splits the engine torque two ways, allowing each output to spin at a different speed. The differential has three jobs:

1.) To aim the engine power at the wheels

2.)To act as the final gear reduction in the vehicle, slowing the rotational speed of the transmission one final time before it hits the wheels

3.)To transmit the power to the wheels while allowing them to rotate at different speeds (This is the one that earned the differential its name.)




I'll will start with the simplest type of differential, called an open differential. When a car is driving straight down the road, both drive wheels are spinning at the same speed. The input pinion is turning the ring gear and cage, and none of the pinions within the cage are rotating -- both side gears are effectively locked to the cage. Note that the input pinion is a smaller gear than the ring gear; this is the last gear reduction in the car. You may have heard terms like rear axle ratio or final drive ratio. These refer to the gear ratio in the differential. If the final drive ratio is 4.10, then the ring gear has 4.10 times as many teeth as the input pinion gear. The pinions in the cage start to spin as the car begins to turn, allowing the wheels to move at different speeds. The inside wheel spins slower than the cage, while the outside wheel spins faster.

The clutch-type LSD is probably the most common version of the limited slip differential. This type of LSD has all of the same components as an open differential, but it adds a spring pack and a set of clutches. Some of these have a cone clutch that is just like the synchronizers in a manual transmission. The spring pack pushes the side gears against the clutches, which are attached to the cage. Both side gears spin with the cage when both wheels are moving at the same speed, and the clutches aren't really needed...the only time the clutches step in is when something happens to make one wheel spin faster than the other, as in a turn. The clutches fight this behavior, wanting both wheels to go the same speed. If one wheel wants to spin faster than the other, it must first overpower the clutch. The stiffness of the springs combined with the friction of the clutch determine how much torque it takes to overpower it. Getting back to the situation in which one drive wheel is on the ice and the other one has good traction: With this limited slip differential, even though the wheel on the ice is not able to transmit much torque to the ground, the other wheel will still get the torque it needs to move. The torque supplied to the wheel not on the ice is equal to the amount of torque it takes to overpower the clutches. The result is that you can move forward, although still not with the full power of your car.


The Torsen differential is a purely mechanical device; it has no electronics, clutches or viscous fluids. The Torsen (from Torque Sensing) works as an open differential when the amount of torque going to each wheel is equal. As soon as one wheel starts to lose traction, the difference in torque causes the gears in the Torsen differential to bind together. The design of the gears in the differential determines the torque bias ratio. For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction.
These devices are often used in high-performance and all-wheel-drive vehicles(EVO8). Like the viscous coupling, they are often used to transfer power between the front and rear wheels. In this application, the Torsen is superior to the viscous coupling because it transfers torque to the stable wheels before the actual slipping occurs. However, if one set of wheels loses traction completely, the Torsen differential will be unable to supply any torque to the other set of wheels. The bias ratio determines how much torque can be transferred, and five times zero is zero.



The viscous coupling is often found in all-wheel-drive vehicles(STi). It is commonly used to link the back wheels to the front wheels so that when one set of wheels starts to slip, torque will be transferred to the other set.
The viscous coupling has two sets of plates inside a sealed housing that is filled with a thick fluid, as shown in below. One set of plates is connected to each output shaft. Under normal conditions, both sets of plates and the viscous fluid spin at the same speed. When one set of wheels tries to spin faster, perhaps because it is slipping, the set of plates corresponding to those wheels spins faster than the other. The viscous fluid, stuck between the plates, tries to catch up with the faster disks, dragging the slower disks along. This transfers more torque to the slower moving wheels...the wheels that are not slipping. When a car is turning, the difference in speed between the wheels is not as large as when one wheel is slipping. The faster the plates are spinning relative to each other, the more torque the viscous coupling transfers. The coupling does not interfere with turns because the amount of torque transferred during a turn is so small. However, this also highlights a disadvantage of the viscous coupling: No torque transfer will occur until a wheel actually starts slipping. A simple experiment with an egg will help explain the behavior of the viscous coupling. If you set an egg on the kitchen table, the shell and the yolk are both stationary. If you suddenly spin the egg, the shell will be moving at a faster speed than the yolk for a second, but the yolk will quickly catch up. To prove that the yolk is spinning, once you have the egg spinning quickly stop it and then let go...the egg will start to spin again (unless it is hard boiled). In this experiment, we used the friction between the shell and the yolk to apply force to the yolk, speeding it up. When we stopped the shell, that friction...between the still-moving yolk and the shell...applied force to the shell, causing it to speed up. In a viscous coupling, the force is applied between the fluid and the sets of plates in the same way as between the yolk and the shell.



I can't think if I forgot anytype or not but I'm too tired to care. I can go back to sleep now. Thanks for reading.
 

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Re: How Diff\'s work. (VERY LONG)

WHY????????????????????????????????????????????????
 

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Re: How Diff\'s work. (VERY LONG)

Craig201MPH said:
die in a differential fluid fire
Man that would have to smell terrible, and be awefully hot, but yeah I think it would to the trick. :thumb:
 

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Re: How Diff\'s work. (VERY LONG)

Oh, there is no bandwagon here. This guy has created a persona that everybody hates individually. To stoop so low to fucking copy and past off a popular website has to be the most pathetic attempt at social acceptance I have ever seen. YOU ARE NOT SMART! YOU ARE NOT LIKED! Shall I continue? Tanked, you just shot yourself in the foot....and with the Alley's boredom at an all time high...I thank you.
 

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Re: How Diff\'s work. (VERY LONG)

Yeah, but he sure did boost his word count /images/graemlins/laughing.gif /images/graemlins/laughing.gif
 

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Re: How Diff\'s work. (VERY LONG)

Tanked said:
I was up, so I decided to put down everything I know about differentials. I took a lot of time, so I hope I don't come off as some kind of smart-ass.

So you came on here and LIED to us because you know very well that youre a dumbass and wanted to appear as if youre not? Listen here dipshit, I dont THINK youre a dumbass, I KNOW you are. Im not joking around here...Im dead serious. You are by far one of the least intelligent people Ive EVER been unfortunate enough to deal with. I legitimately think youre fuckin dumber than dogshit. There are some animals that would do better than you here. To communicate to you, wed have to stoop to your level and resort to using commands like "SIT!" "STAY!" "HEEL!", "GO POTTY!", "OUT!". Its too bad that you dont have a tail, or we could just tie a milkbone to it and watch you run around in a circle. Im gonna guess that even YOU think youre a dumbass. What else would motivate you do do what you just did? No matter how hard you tried, you couldnt think of one intelligent thing to say. So what do you do? You went and posted something at random about something we dont care about whatsoever and called it your own. Diddnt they teach you that they call that plagiarism in school? Whats worse is that if that was copyrighted material thats probably against the law. Seriously, get off this fuckin board.
 

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Re: How Diff\'s work. (VERY LONG)

Smokin said:
Tanked said:
I was up, so I decided to put down everything I know about differentials. I took a lot of time, so I hope I don't come off as some kind of smart-ass.

So you came on here and LIED to us because you know very well that youre a dumbass and wanted to appear as if youre not? Listen here dipshit, I dont THINK youre a dumbass, I KNOW you are. Im not joking around here...Im dead serious. You are by far one of the least intelligent people Ive EVER been unfortunate enough to deal with. I legitimately think youre fuckin dumber than dogshit. There are some animals that would do better than you here. To communicate to you, wed have to stoop to your level and resort to using commands like "SIT!" "STAY!" "HEEL!", "GO POTTY!", "OUT!". Its too bad that you dont have a tail, or we could just tie a milkbone to it and watch you run around in a circle. Im gonna guess that even YOU think youre a dumbass. What else would motivate you do do what you just did? No matter how hard you tried, you couldnt think of one intelligent thing to say. So what do you do? You went and posted something at random about something we dont care about whatsoever and called it your own. Diddnt they teach you that they call that plagiarism in school? Whats worse is that if that was copyrighted material thats probably against the law. Seriously, get off this fuckin board.
/images/graemlins/laughing.gif :rofl:
 

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Re: How Diff\'s work. (VERY LONG)

This is just a hilarious thread. I keep laughing and shaking my head. Smoke actually sounds a bit concerned for Tanked's mental health ... as if he can't bring himself to believe that a human being could attempt such an obvious cry for attention. I just can't stop chuckling.
 

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Re: How Diff\'s work. (VERY LONG)

ORIGINALGTS said:
Craig201MPH said:
die in a differential fluid fire
Man that would have to smell terrible, and be awefully hot, but yeah I think it would to the trick. :thumb:
I'll take it one step further for even more stink.......

die in a synthetic differential fluid fire /images/graemlins/laughing.gif
 
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