Stiffness of a rectilinear suspension with automatic length compensation branches

This paper focuses on the stiffness of a rectilinear independent suspension whose alignment parameters are invariable in mechanism theory during jounce and rebound. The suspension is a kind of multilink mechanism, the kinematic chains of which consist of 3-RRR distance compensation branches. However the capacity to keep a straight line motion depends on the resultant stiffness of the suspension. Therefore, this paper proposes a methodology to investigate the equivalent stiffness of the suspension. The fact that the resultant stiffness of the suspension is subjected to the stiffness of each 3-RRR distance compensation linkage raises a particular difficulty to build the model. So the deformation and the deflection of each branch are established first, and then the six-dimensional stiffness of the suspension is equivalently expressed in terms of the material properties of the four chains.

► This study proposes a novel suspension mechanism with automatic length compensation branches.
► This study proposes a stiffness of the suspension by avoiding solving inverse positions.
► Numerical examples show that the method can be used to optimize the design.