Currently, the more common suspensions include MacPherson independent suspension, double wishbone independent suspension, double A-arm independent suspension, multi-link independent suspension, torsion beam non-independent suspension, and solid axle non-independent suspension, etc.
Non-independent Suspension
Characteristics: Simple structure, reliable operation, long service life
As the name suggests, the structure of a non-independent suspension is that both wheels on each side are installed at the ends of a single integral axle, and the axle is connected to the frame through elastic components. When one wheel jumps due to road undulations, it will affect the positioning parameters of the other wheel.
Longitudinal leaf spring non-independent suspension
Representative models: Minivans, trucks, buses
In this type of suspension, the elastic element is not the common coil spring but a longitudinally installed leaf spring. The advantage of this structure lies in its excellent load-bearing capacity. Currently, this suspension is widely used in the front and rear suspensions of trucks, and some off-road vehicles also adopt this structure.
Coil spring non-independent suspension
Representative model: Jeep Wrangler
Independent suspension
Characteristics: Wheels do not interfere with each other, structure is slightly more complex
Vehicles with independent suspension have each wheel on both sides independently connected to the frame or body with elastic elements. Compared with non-independent suspension, the wheels on both sides can move relatively freely with less mutual interference. However, some independent suspension structures are relatively complex and have higher costs.
MacPherson independent suspension
Motion characteristics: The wheels move along the kingpin.
Representative models: Chery QQ, Ford Focus, 9th generation Accord, Subaru Forester, etc.
The MacPherson independent suspension is a common form of front suspension. The elastic strut suspension and shock absorber strut suspension mentioned in some materials actually refer to the MacPherson independent suspension. It has the advantages of compact structure and high integration, thus occupying less space. This is one of the reasons why it is widely used in front suspensions. With the same vehicle width, the engine compartment space can be larger, making it easier to arrange mechanical parts, and the design of the front energy absorption area is more flexible, and the passenger compartment space performance is better.
Of course, the disadvantages of the MacPherson independent suspension are also obvious. Due to its structure, it has poor lateral rigidity. It is insufficient in suppressing vehicle pitch (also known as the "nose dive phenomenon") and torque steer.
The MacPherson independent suspension can be regarded as the top choice in the current automotive industry. It can be found in small cars, compact cars, midsize cars, sports cars, and SUVs. Even some models that previously used other independent suspensions have switched to the MacPherson independent suspension during their updates, such as Mazda ATENZA and the 9th generation Accord. The reasons for this are related to its simple structure and low cost. Besides being used in front suspensions, some models also use the MacPherson independent suspension in their rear suspensions. Just like in front suspensions, its advantages are low cost and simple structure. However, its disadvantages are that the upper positioning still relies on the elastic strut, resulting in relatively weaker rigidity and stability compared to multi-link suspensions.
Double wishbone independent suspension (double A-arm independent suspension, double wishbone independent suspension)
Motion characteristics: The wheels swing in the vehicle's transverse plane.
Representative models: 4th generation Discovery, GAC Trumpchi GA5, Toyota Crown
The double wishbone and double A-arm independent suspensions we are familiar with both have the structure where the wheels swing in the vehicle's transverse plane. They are both composed of two three-point linkages (A-arms) and one two-point linkage. Compared to the MacPherson independent suspension, it has better lateral stiffness; it suppresses vehicle pitch better and provides engineers with higher design freedom. Its disadvantages are also obvious. Due to its slightly more complex structure, it occupies more space, and the increased number of linkages makes it more expensive.