What is torque steer?
The reason why the front-drive will become the mainstream production car, because it reduces the maximum mechanical space, the passenger has the most spacious seating space, eliminating the need for drive shaft also We can save a lot of costs for the manufacturers. Moreover, for ordinary driving, the front-drive after drive has a relatively better handling, slippery surfaces less prone to slipping.
“front-drive layout to maximize the mechanical compression of space placed, the more room for passengers.”
[ 123] but everything is always good foundation, that when the transverse engine horsepower is getting bigger, the problem will gradually appear. Because the FF vehicle steering shaft and responsible for power transmission, but because of the position of the gearbox, often a long shaft around a shorter design, when suddenly a large torque output from the transmission output shaft to approximately when the two drive shafts, because of the different moments and will cause deviation direction of travel of the vehicle, which is the so-called torque steer. In other words, the main factors causing the steering torque is instead of driving, because the torque output is too large, thus causing the vehicle ldquo; non-driver autonomy rdquo; steering.
Why would the torque steer?
Why about unequal length drive shafts transmit torque will cause different result? The reason for the suspension and gimbal is the culprit. First, the geometry FF vehicle drive shaft and axle are not coincident, turn the drive shaft to bend in order to connect two small wheels, turning the place, it is connected by the universal joint. Although the joint may vary movable transmission direction, but the joint is not a panacea, Flanagan shaft after the change in direction of the drive shaft is changed while the direction will have some swinging, so to install an anti-whip fulcrum role played solid, if not fixed fulcrum, the rear end of the drive shaft will be like a blender as swinging. When the drive shaft out of line after the preganglionic universal time, the reaction force against the pivot joint must be put into a swinging force conversion torsion force, but as long as the friction joint consumption control properly, the gimbal torque transmission efficiency is very high, especially in the case of changing the small angle drive, torque about the differences may be caused by non-friction lossesOften small.
“Since the wheel axle connection requires a certain degree of freedom, so that the geometrical position of the hub axle does not completely coincide with the”
When the left and right drive shaft unequal, both ends of an angle about the universal joint transmission is not the same, the greatest impact force magnitude by anti-swinging fulcrum, the force is directly proportional to the angle drive SIN function, the function near the proximity angle 180 degrees angle change is very sensitive. Meanwhile, since the fulcrum is fixed on the suspension, the suspension is a certain degree of freedom, when the car is accelerating, due to the shift of the center of gravity, a relatively small amount of the front elevation, time, before the shock absorbing cylinder is elongated, side short shaft angle change is large, under the action of the torsion relatively large amplitude extending in the front wheel, the vehicle front suspension FF are many forms McPherson, shock-absorbing wheel cylinder itself is supported axis, it will produce a change if the front wheel extends camber angle, a slight change in the camber angle can be changed wheel contact points, so torque steer effect is likely to be enlarged.
If both ends of the shaft length change and the like, the same angle on both sides of the drive, then this action can be effectively suppressed. It will not change if the wheel camber reach, then the torque steer effect will not have been over-amplification, the problem is not so serious. Simply put, due to the increase in violent engine power output, universal joints caused by different due to the different angles of transmission efficiency, and because of increased engine power output violently, increase the speed, the front suspension is stretched, causing a small camber angle change, the more magnified the problem, eventually leading to the occurrence of torque steer.
Now, the problem has been solved, Magotan axle design purpose is to prevent the occurrence of torque steer when excessive torque will be broken axle. Engineers will select Geshitu longer axle design into two sections, an increase of some intermediate shaft, which allows an equal length on both sides of the axle, weaken torque steer, which is used in most of today FF car design the way.
“VOLVO S40 front axle with sub-type design, as long as the left and right axle”
torque steerHow to avoid
To solve the problem of torque steer FF car, the best that can be made as long as the drive shaft, Subaru’s symmetrical drivetrain is the case, both front and rear, left and right drive shafts of equal length or with precise and multi-link double-wishbone front suspension, camber change can be suppressed, the maximum torque steer alleviate the problems, but also the use of modern electronic torque control left and right wheels will be relatively adjusted as , can greatly reduce the occurrence of steering torque.
“about the AWD Subaru symmetrical full-time four-wheel drive system, the left and right drive shafts of equal length.”
In fact, the mechanical structure and layout, front-drive axle same can be done about as long, but the plant is through early in the design trade-offs, usually civilian car (car to be preoccupied with perfect control, so extreme, it is not in this the range) only for as long as the left and right axle differential gear box modified arrangement, the consequences will affect the economy of the engine position, form and the like of the engine compartment space utilization, it is clear pay.
Summary:
than it seems, front-drive layout due to its characteristics, torque steer handling problems will have an impact, especially in high-powered supercharged models, to want to avoid torque steer on hard acceleration, good handling, not only have an excellent suspension system, but also has one pair of sturdy enough, well-designed left and right drive shafts with each other, the control wheel to achieve the best driving results. This explains why there are cases before the modification owners and axle fracture occurs dress up more powerful engine, visible in the front drive shaft also plays a very important role.