Suspension System
SUSPENSION SYSTEM
FUNCTIONS OF SUSPENSION SYSTEMS:
To provide good ride and handling performance –
–providing chassis isolation
–ensuring that the wheels follow the road profile
–very little tire load fluctuation
To ensure that steering control is maintained during manoeuvring –
–wheels to be maintained in the proper position wrt road surface
To ensure that the vehicle responds favourably to control forces produced by the tires during
–longitudinal braking
–accelerating forces,
–lateral cornering forces and
–braking and accelerating torques
–this requires the suspension geometry to be designed to resist squat, dive and roll of the vehicle body
To provide isolation from high frequency vibration from tire excitation
–Prevent transmission of ‘road noise’ to the vehicle body
TYPES OF SUSPENSION SYSTEMS:
All suspension systems are mainly classified as:
1) Dependent Systems:
• It mainly consists of a solid axle supported by leaf spring and shock absorbers
•Motion of a wheel on one side of the vehicle is dependent on the motion of its partner on the other side
•Rarely used in modern passenger cars
–Cannot give good ride
–Cannot control high braking and accelerating torques
–High unsprung mass due to heavy solid axle
•Used in some commercial vehicles
2) Semi dependent system:
•the rigid connection between pairs of wheels is replaced by a compliant link.
•a beam which can bend and flex providing both positional control of the wheels as well as compliance.
•tend to be simple in construction but lack scope for design flexibility
•Additional compliance can be provided by rubber or hydro-elastic springs.
•Wheel camber is, in this case, the same as body roll
3) Independent systems:
So-named because the front wheel's suspension systems are independent of each other
• Motion of wheel pairs is independent, so that a disturbance at one wheel is not
FUNCTIONS OF SUSPENSION SYSTEMS:
To provide good ride and handling performance –
–providing chassis isolation
–ensuring that the wheels follow the road profile
–very little tire load fluctuation
To ensure that steering control is maintained during manoeuvring –
–wheels to be maintained in the proper position wrt road surface
To ensure that the vehicle responds favourably to control forces produced by the tires during
–longitudinal braking
–accelerating forces,
–lateral cornering forces and
–braking and accelerating torques
–this requires the suspension geometry to be designed to resist squat, dive and roll of the vehicle body
To provide isolation from high frequency vibration from tire excitation
–Prevent transmission of ‘road noise’ to the vehicle body
TYPES OF SUSPENSION SYSTEMS:
All suspension systems are mainly classified as:
1) Dependent Systems:
• It mainly consists of a solid axle supported by leaf spring and shock absorbers
•Motion of a wheel on one side of the vehicle is dependent on the motion of its partner on the other side
•Rarely used in modern passenger cars
–Cannot give good ride
–Cannot control high braking and accelerating torques
–High unsprung mass due to heavy solid axle
•Used in some commercial vehicles
2) Semi dependent system:
•the rigid connection between pairs of wheels is replaced by a compliant link.
•a beam which can bend and flex providing both positional control of the wheels as well as compliance.
•tend to be simple in construction but lack scope for design flexibility
•Additional compliance can be provided by rubber or hydro-elastic springs.
•Wheel camber is, in this case, the same as body roll
3) Independent systems:
So-named because the front wheel's suspension systems are independent of each other
• Motion of wheel pairs is independent, so that a disturbance at one wheel is not