Suspention Types
The four wheels of a car work together in two independent systems-the two wheels connected by the front axle and the two wheels connected eby the rear axle.That means that a car usually does have a different type of suspention on the front and back.Much is determined by whether a rigid axle binds the wheels or if the wheeels are permitted to move independently.
The former arrangement is known as a non-independent system, while the latter arrangement is known as an independentsystem.Some of the common types of front and back suspensiona are typically used on mainstream cars.
Non-independent suspension
Live/Dead Axle suspension
Until the late 1970s, most cars still used this simple non-independent suspensions, especially at the rear axle.Basically, it is a rigid axle fixed between left and right wheels. The car body is suspended by leaf springs or coil springs on the axle unit.If the axle is the driving axle, it is called live Axle.Live axle is very heavy. It consists of the final drive/differential, drive shafts and a strong tube enclosing all these things..Since the whole axle is rigidly fixed to the wheels instead of suspended by springs, the so-called Unsprung Weight is very high. Without the driving mechanism incorporated, dead axle has much less unsprung weight, so its ride quality is better than Live Axle.
Independent suspension
1. MacPherson strut is the most widely used froont suspension system, which combines a shock absorber and a coil spring into a single unit .. This provide a more compact and lighter suspention system that can be used for front-wheel drive vehicles.
The shock absober, strut, and spindle are a combined unit that is supported by the coil spring at the upper end and by the lower control arm at the bottom. The lower arm is held in position by a sway bar and frame-mounted rod called a strut rod, or by a stabilizer bar that functions as a combined strut rod and sway bar.
2. Double-wishbone suspension
To many suspention designers, double-wishbone suspention is the most idea suspention.It can be used in front and rear wheels, it is independent and most important, and it has near perfect camber control.For 40 years and even today, this is the first choice for racing cars, sports cars and demanding sedans.
Basically, double-wishbone suspension always maintains the wheel perpendicular to the road surface, irrepective of the wheel’s movement.This ensures good handing.
3. Multi-link suspension
Since the late 1980s, muti-link rear suspention is increasingly used in modern sedans and coupes, including Nissan 200SX,Infiniti Q45,Mercedes S-class and Bmw 3-Series ect.
It’s difficult to describe its construction because it is not strictly defined.In theroy, any indeoendent suspention having 3 control arms or more are multi-link.Different designs may have very different geometry, and characteristic, for example, BWM’s multi-link looks like a letter “Z’.thus gave its name “Z-axle”. relatively space-engaging but offers very good handling;Honda Accord’s multi-link is essentially a double-wishbone suspention added with the fifth control arm.Audi A4’s Quadralink front susupentions has four links.It looks alike double-wishbone suspension but eliminates torque steer.
4. Torsion beam suspension
Most modern mini cars up to Most modern mini cars up to C-segment9FOR INSTANCE,VW Golf) employ torsion beam as the rear suspention.Why?Compare with double-wishbone, multi-link suspention, it engages width of the car, thus enable greater rear seat room.It’s cheaper too.Compare with MacPherson strut, its shock absorber is shorter and can be inclined steeply away from the vertical, thus engage less boot space.
In fact, torsion beam suspention is only half –independent-ther ia a torsion beam connecting both wheels together, which allows limited degree of freedom when forced.For some less demanding compact cars, this save the anti-roll bars.On the contrary, it doesn’t provide the same level of ride of ride and handling as double-wishbone or mutillink suspentions, although in reality it si superior to its only direct competitor,MacPherson strut.
auther:Candywww.sinodisel.com
